feat(curriculum): add luhn algorithm project (#52443)

Co-authored-by: Dario-DC <105294544+Dario-DC@users.noreply.github.com> Co-authored-by: Krzysztof G <60067306+gikf@users.noreply.github.com>
2026-05-28 18:26:54 +00:00 · 2023-12-19 23:18:02 +02:00
parent 8f579cdec6
commit 08b01d1499
38 changed files with 2354 additions and 0 deletions
@@ -1191,6 +1191,10 @@
        "title": "Upcoming Python Project",
        "intro": ["placeholder"]
      },
+      "learn-how-to-work-with-numbers-and-strings-by-implementing-the-luhn-algorithm": {
+        "title": "Learn How to Work with Numbers and Strings by Implementing the Luhn Algorithm",
+        "intro": ["", ""]
+      },
      "learn-classes-and-objects-by-building-a-sudoku-solver": {
        "title": "Learn Classes and Objects by Building a Sudoku Solver",
        "intro": [
@@ -0,0 +1,10 @@
+---
+title: Introduction to the Learn How to Work with Numbers and Strings by Implementing the Luhn Algorithm
+block: learn-how-to-work-with-numbers-and-strings-by-implementing-the-luhn-algorithm
+superBlock: upcoming-python
+isBeta: true
+---
+
+## Introduction to the Learn How to Work with Numbers and Strings by Implementing the Luhn Algorithm
+
+This is a test for the new project-based curriculum.
@@ -0,0 +1,157 @@
+{
+  "name": "Learn How to Work with Numbers and Strings by Implementing the Luhn Algorithm",
+  "isUpcomingChange": true,
+  "usesMultifileEditor": true,
+  "hasEditableBoundaries": true,
+  "dashedName": "learn-how-to-work-with-numbers-and-strings-by-implementing-the-luhn-algorithm",
+  "order": 5,
+  "time": "5 hours",
+  "template": "",
+  "required": [],
+  "superBlock": "upcoming-python",
+  "superOrder": 20,
+  "isBeta": true,
+  "challengeOrder": [
+    {
+      "id": "6565a536ba1f9f25bd30e88b",
+      "title": "Step 1"
+    },
+    {
+      "id": "656877c202f44995ed952608",
+      "title": "Step 2"
+    },
+    {
+      "id": "656877f71bba2b97acedf9af",
+      "title": "Step 3"
+    },
+    {
+      "id": "656878585631369a6b2d2191",
+      "title": "Step 4"
+    },
+    {
+      "id": "6568789edf2ed39c81983cc4",
+      "title": "Step 5"
+    },
+    {
+      "id": "65687946130b0ea10aa19b75",
+      "title": "Step 6"
+    },
+    {
+      "id": "6569b831a07d7154c793301b",
+      "title": "Step 7"
+    },
+    {
+      "id": "656879613a96aba21cbe80b9",
+      "title": "Step 8"
+    },
+    {
+      "id": "656879a66338b2a461d5d307",
+      "title": "Step 9"
+    },
+    {
+      "id": "656879c6f35a85a59c06b3a7",
+      "title": "Step 10"
+    },
+    {
+      "id": "656b4638cb8bcf2729afe9a9",
+      "title": "Step 11"
+    },
+    {
+      "id": "656b475b394390334828eb12",
+      "title": "Step 12"
+    },
+    {
+      "id": "656b47dc2cf39e37025dc033",
+      "title": "Step 13"
+    },
+    {
+      "id": "656b481ec4976439565a78b2",
+      "title": "Step 14"
+    },
+    {
+      "id": "656879e1c749d7a6c5eba2d2",
+      "title": "Step 15"
+    },
+    {
+      "id": "65687a005aba3ea815b84e68",
+      "title": "Step 16"
+    },
+    {
+      "id": "65687a8253766cac4c99c57f",
+      "title": "Step 17"
+    },
+    {
+      "id": "65687a923dd792ad339f9c09",
+      "title": "Step 18"
+    },
+    {
+      "id": "65687ad86596e0af38640a84",
+      "title": "Step 19"
+    },
+    {
+      "id": "65687b182c2a8fb1470e0b97",
+      "title": "Step 20"
+    },
+    {
+      "id": "65687b48f2201ab32e06c37c",
+      "title": "Step 21"
+    },
+    {
+      "id": "65687b68003a61b46fe691f0",
+      "title": "Step 22"
+    },
+    {
+      "id": "65687b8eb0bbf7b5d41b610b",
+      "title": "Step 23"
+    },
+    {
+      "id": "65687bbfd9a7d6b78cd5b5cf",
+      "title": "Step 24"
+    },
+    {
+      "id": "65687c2fd0fec7ba9fb8af30",
+      "title": "Step 25"
+    },
+    {
+      "id": "65687c8d86e18cbd775a53c9",
+      "title": "Step 26"
+    },
+    {
+      "id": "65687da2e60409c45595bbe1",
+      "title": "Step 27"
+    },
+    {
+      "id": "65687db6a9fcf3c548a6c1b7",
+      "title": "Step 28"
+    },
+    {
+      "id": "65687dd4b641fdc67d7de487",
+      "title": "Step 29"
+    },
+    {
+      "id": "65687e069cf4e0c85b0a06b1",
+      "title": "Step 30"
+    },
+    {
+      "id": "65687e0ed12e20c91811a48d",
+      "title": "Step 31"
+    },
+    {
+      "id": "65687e294ef2bdca637fb213",
+      "title": "Step 32"
+    },
+    {
+      "id": "65687e457ab1c4cb8c3fe7c8",
+      "title": "Step 33"
+    },
+    {
+      "id": "65687f47f9001dd35bdcd5ab",
+      "title": "Step 34"
+    },
+    {
+      "id": "656880227dab4bd8fbc02d41",
+      "title": "Step 35"
+    }
+  ],
+  "helpCategory": "Python"
+}
@@ -0,0 +1,54 @@
+---
+id: 6565a536ba1f9f25bd30e88b
+title: Step 1
+challengeType: 20
+dashedName: step-1
+---
+
+# --description--
+
+In this project, you will implement the Luhn Algorithm. This algorithm is a formula to validate a variety of identification numbers.
+
+<!-- TODO: Maybe cover `if __name__ == '__main__'` -->
+<!-- Might not make sense, because import is not covered yet -->
+<!-- https://docs.python.org/3/reference/import.html?highlight=__name__#import-related-module-attributes -->
+
+Start by declaring a function called `main`. Use the `pass` keyword to avoid an error.
+
+# --hints--
+
+You should have `def main():` in your code.
+
+```js
+({
+    test: () => {
+        assert(__pyodide.runPython(`
+        import inspect
+        a = __locals.get("main")
+        inspect.isfunction(a)
+        `))
+    }
+})
+```
+
+You should have `pass` in your code.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const pass = __helpers.python.getDef("\n"+transformedCode, "main");
+        assert.include(pass?.function_body, "pass");
+    }
+})
+```
+
+# --seed--
+
+## --seed-contents--
+
+```python
+--fcc-editable-region--
+
+--fcc-editable-region--
+```
@@ -0,0 +1,50 @@
+---
+id: 656877c202f44995ed952608
+title: Step 2
+challengeType: 20
+dashedName: step-2
+---
+
+# --description--
+
+Replace the `pass` statement with a variable named `card_number` and a value of `4111-1111-4555-1142`.
+
+# --hints--
+
+You should have `card_number = "4111-1111-4555-1142"` within the `main` function.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const main = __helpers.python.getDef("\n" + transformedCode, "main");
+        const { function_body } = main;
+
+        assert.match(function_body, / +card_number\s*=\s*('|")4111-1111-4555-1142\1/);
+    }
+})
+```
+
+You should not have a `pass` in your code.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const no_comments = __helpers.python.removeComments(transformedCode);
+        assert.notInclude(no_comments, "pass");
+    }
+})
+```
+
+# --seed--
+
+## --seed-contents--
+
+```py
+--fcc-editable-region--
+def main():
+    pass
+
+--fcc-editable-region--
+```
@@ -0,0 +1,65 @@
+---
+id: 656877f71bba2b97acedf9af
+title: Step 3
+challengeType: 20
+dashedName: step-3
+---
+
+# --description--
+
+Python comes with built-in classes that can help us with string manipulation. One of them is the `str` class. It has a method called `maketrans` that can help us create a translation table. This table can be used to replace characters in a string:
+
+```python
+str.maketrans({'t': 'c', 'l': 'b'})
+```
+
+The above, when called on a string, will replace all `t` characters with `c` and all `l` characters with `b`.
+
+Create a variable called `card_translation` and assign it a translation table to replace all `-` and ` ` characters with an empty string.
+
+# --hints--
+
+You should create a `card_translation` variable within `main`.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const main = __helpers.python.getDef("\n" + transformedCode, "main");
+        const { function_body } = main;
+
+        assert.match(function_body, / +card_translation\s*=/);
+    }
+})
+```
+
+You should assign `card_translation` a value of `str.maketrans({'-': '', ' ': ''})`.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const main = __helpers.python.getDef("\n" + transformedCode, "main");
+        const { function_body } = main;
+
+        const allowedMatches = [
+            / +card_translation\s*=\s*str\.maketrans\(\s*\{\s*(['"])-\1\s*:\s*(['"])\2\s*,\s*(['"]) \3\s*:\s*(['"])\4\s*\}\s*\)/,
+            / +card_translation\s*=\s*str\.maketrans\(\s*\{\s*(['"]) \1\s*:\s*(['"])\2\s*,\s*(['"])-\3\s*:\s*(['"])\4\s*\}\s*\)/,
+        ];
+        const anyMatch = allowedMatches.some((match) => match.test(function_body));
+        assert.isTrue(anyMatch);
+    }
+})
+```
+
+# --seed--
+
+## --seed-contents--
+
+```py
+--fcc-editable-region--
+def main():
+    card_number = '4111-1111-4555-1142'
+    
+--fcc-editable-region--
+```
@@ -0,0 +1,61 @@
+---
+id: 656878585631369a6b2d2191
+title: Step 4
+challengeType: 20
+dashedName: step-4
+---
+
+# --description--
+
+Defining the translation does not in itself translate the string. The `translate` method must be called on the string to be translated with the translation table as an argument:
+
+```py
+my_string = "tamperlot"
+translation_table = str.maketrans({'t': 'c', 'l': 'b'})
+translated_string = my_string.translate(translation_table)
+```
+
+Create a variable called `translated_card_number` and assign it the result of calling the `translate` method on `card_number` with `card_translation` as an argument.
+
+# --hints--
+
+You should create a `translated_card_number` variable within `main`.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const main = __helpers.python.getDef("\n" + transformedCode, "main");
+        const { function_body } = main;
+
+        assert.match(function_body, / +translated_card_number\s*=/);
+    }
+})
+```
+
+You should assign `translated_card_number` a value of `card_number.translate(card_translation)`.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const main = __helpers.python.getDef("\n" + transformedCode, "main");
+        const { function_body } = main;
+
+        assert.match(function_body, / +translated_card_number\s*=\s*card_number\.translate\(\s*card_translation\s*\)/);
+    }
+})
+```
+
+# --seed--
+
+## --seed-contents--
+
+```py
+--fcc-editable-region--
+def main():
+    card_number = '4111-1111-4555-1142'
+    card_translation = str.maketrans({'-': '', ' ': ''})
+    
+--fcc-editable-region--
+```
@@ -0,0 +1,40 @@
+---
+id: 6568789edf2ed39c81983cc4
+title: Step 5
+challengeType: 20
+dashedName: step-5
+---
+
+# --description--
+
+Print the translated card number to the console.
+
+# --hints--
+
+You should print `translated_card_number` to the console.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const main = __helpers.python.getDef("\n" + transformedCode, "main");
+        const { function_body } = main;
+
+        assert.match(function_body, / +print\(\s*translated_card_number\s*\)/);
+    }
+})
+```
+
+# --seed--
+
+## --seed-contents--
+
+```py
+--fcc-editable-region--
+def main():
+    card_number = '4111-1111-4555-1142'
+    card_translation = str.maketrans({'-': '', ' ': ''})
+    translated_card_number = card_number.translate(card_translation)
+    
+--fcc-editable-region--
+```
@@ -0,0 +1,40 @@
+---
+id: 65687946130b0ea10aa19b75
+title: Step 6
+challengeType: 20
+dashedName: step-6
+---
+
+# --description--
+
+Call the `main` function at the end of your script.
+
+# --hints--
+
+You should have `main()` outside of the `main` function.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        assert.match(transformedCode, /\nmain\(\s*\)/);
+    }
+})
+```
+
+# --seed--
+
+## --seed-contents--
+
+```py
+--fcc-editable-region--
+def main():
+    card_number = '4111-1111-4555-1142'
+    card_translation = str.maketrans({'-': '', ' ': ''})
+    translated_card_number = card_number.translate(card_translation)
+
+    print(translated_card_number)
+
+
+--fcc-editable-region--
+```
@@ -0,0 +1,46 @@
+---
+id: 656879613a96aba21cbe80b9
+title: Step 8
+challengeType: 20
+dashedName: step-8
+---
+
+# --description--
+
+Within your `main` function, call the `verify_card_number` function and pass in the `translated_card_number` variable as an argument.
+
+# --hints--
+
+You should have `verify_card_number(translated_card_number)` within the `main` function.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const main = __helpers.python.getDef("\n" + transformedCode, "main");
+        const { function_body } = main;
+
+        assert.match(function_body, / +verify_card_number\(\s*translated_card_number\s*\)/);
+    }
+})
+```
+
+# --seed--
+
+## --seed-contents--
+
+```py
+def verify_card_number(card_number):
+    pass
+
+--fcc-editable-region--
+def main():
+    card_number = '4111-1111-4555-1142'
+    card_translation = str.maketrans({'-': '', ' ': ''})
+    translated_card_number = card_number.translate(card_translation)
+
+    print(translated_card_number)
+
+--fcc-editable-region--
+main()
+```
@@ -0,0 +1,78 @@
+---
+id: 656879a66338b2a461d5d307
+title: Step 9
+challengeType: 20
+dashedName: step-9
+---
+
+# --description--
+
+<!-- TODO: Find better places to split explanation up. -->
+
+The Luhn algorithm is as follows:
+
+1. From the right to left, double the value of every second digit; if the product is greater than 9, sum the digits of the products.
+2. Take the sum of all the digits.
+3. If the sum of all the digits is a multiple of `10`, then the number is valid; else it is not valid.
+
+Assume an example of an account number "7992739871" that will have a check digit added, making it of the form 7992739871x:
+
+```markdown
+Account number      7   9  9  2  7  3  9   8  7  1  x
+Double every other  7  18  9  4  7  6  9  16  7  2  x
+Sum 2-char digits   7   9  9  4  7  6  9   7  7  2  x
+```
+
+Replace the `pass` statement with a variable `sum_of_odd_digits` and a value of `0`.
+
+# --hints--
+
+You should have `sum_of_odd_digits = 0` within the `verify_card_number` function.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const verify_card_number = __helpers.python.getDef("\n" + transformedCode, "verify_card_number");
+        const { function_body } = verify_card_number;
+
+        assert.match(function_body, /sum_of_odd_digits\s*=\s*0/);
+    }
+})
+```
+
+You should not have `pass` within the `verify_card_number` function.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const verify_card_number = __helpers.python.getDef("\n" + transformedCode, "verify_card_number");
+        const { function_body } = verify_card_number;
+
+        assert.notMatch(function_body, /pass/);
+    }
+})
+```
+
+# --seed--
+
+## --seed-contents--
+
+```py
+--fcc-editable-region--
+def verify_card_number(card_number):
+    pass
+
+--fcc-editable-region--
+def main():
+    card_number = '4111-1111-4555-1142'
+    card_translation = str.maketrans({'-': '', ' ': ''})
+    translated_card_number = card_number.translate(card_translation)
+
+    print(translated_card_number)
+
+    verify_card_number(translated_card_number)
+
+main()
+```
@@ -0,0 +1,59 @@
+---
+id: 656879c6f35a85a59c06b3a7
+title: Step 10
+challengeType: 20
+dashedName: step-10
+---
+
+# --description--
+
+You have accessed elements (characters) of a string before, using the index operator `[]`. You can also use the index operator to access a range of characters in a string with `string[x:y:h]`:
+
+```python
+my_string = 'camperbot'
+camper = my_string[0:6]
+cp = my_string[0:6:3]
+```
+
+Where `x` is the starting index, `y` is the ending index, and `h` is the step (the amount of characters to skip over).
+
+Create a variable named `card_number_reversed` and assign it the value of the first 4 characters of `card_number`.
+
+# --hints--
+
+You should have `card_number_reversed = card_number[0:4]` within the `verify_card_number` function.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const verify_card_number = __helpers.python.getDef("\n" + transformedCode, "verify_card_number");
+        const { function_body } = verify_card_number;
+
+        assert.match(function_body, /card_number_reversed\s*=\s*card_number\[0:4\]/);
+    }
+})
+```
+
+
+# --seed--
+
+## --seed-contents--
+
+```py
+--fcc-editable-region--
+def verify_card_number(card_number):
+    sum_of_odd_digits = 0
+    
+--fcc-editable-region--
+def main():
+    card_number = '4111-1111-4555-1142'
+    card_translation = str.maketrans({'-': '', ' ': ''})
+    translated_card_number = card_number.translate(card_translation)
+
+    print(translated_card_number)
+
+    verify_card_number(translated_card_number)
+
+main()
+```
@@ -0,0 +1,50 @@
+---
+id: 656879e1c749d7a6c5eba2d2
+title: Step 15
+challengeType: 20
+dashedName: step-15
+---
+
+# --description--
+
+Remove the `print` call from the `verify_card_number` function.
+
+# --hints--
+
+You should not have a `print` call within the `verify_card_number` function.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const verify_card_number = __helpers.python.getDef("\n" + transformedCode, "verify_card_number");
+        const { function_body } = verify_card_number;
+        const no_comments = __helpers.python.removeComments(function_body);
+        assert.notMatch(no_comments, /print\(/);
+    }
+})
+```
+
+# --seed--
+
+## --seed-contents--
+
+```py
+--fcc-editable-region--
+def verify_card_number(card_number):
+    sum_of_odd_digits = 0
+    card_number_reversed = card_number[::-1]
+    print(card_number_reversed)
+    
+--fcc-editable-region--
+def main():
+    card_number = '4111-1111-4555-1142'
+    card_translation = str.maketrans({'-': '', ' ': ''})
+    translated_card_number = card_number.translate(card_translation)
+
+    print(translated_card_number)
+
+    verify_card_number(translated_card_number)
+
+main()
+```
@@ -0,0 +1,49 @@
+---
+id: 65687a005aba3ea815b84e68
+title: Step 16
+challengeType: 20
+dashedName: step-16
+---
+
+# --description--
+
+Remove the `print` call from the `main` function.
+
+# --hints--
+
+You should not have a `print` call within the `main` function.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const main = __helpers.python.getDef("\n" + transformedCode, "main");
+        const { function_body } = main;
+        const no_comments = __helpers.python.removeComments(function_body);
+        assert.notMatch(no_comments, /print\(/);
+    }
+})
+```
+
+# --seed--
+
+## --seed-contents--
+
+```py
+def verify_card_number(card_number):
+    sum_of_odd_digits = 0
+    card_number_reversed = card_number[::-1]
+
+--fcc-editable-region--
+def main():
+    card_number = '4111-1111-4555-1142'
+    card_translation = str.maketrans({'-': '', ' ': ''})
+    translated_card_number = card_number.translate(card_translation)
+
+    print(translated_card_number)
+
+    verify_card_number(translated_card_number)
+--fcc-editable-region--
+
+main()
+```
@@ -0,0 +1,47 @@
+---
+id: 65687a8253766cac4c99c57f
+title: Step 17
+challengeType: 20
+dashedName: step-17
+---
+
+# --description--
+
+Within the `verify_card_number` function, create a variable `odd_digits` that contains every other digit of the `card_number_reversed` string.
+
+# --hints--
+
+You should have `odd_digits = card_number_reversed[::2]` within the `verify_card_number` function.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const verify_card_number = __helpers.python.getDef("\n" + transformedCode, "verify_card_number");
+        const { function_body } = verify_card_number;
+
+        assert.match(function_body, /odd_digits\s*=\s*card_number_reversed\[::2\]/);
+    }
+})
+```
+
+# --seed--
+
+## --seed-contents--
+
+```py
+--fcc-editable-region--
+def verify_card_number(card_number):
+    sum_of_odd_digits = 0
+    card_number_reversed = card_number[::-1]
+    
+--fcc-editable-region--
+def main():
+    card_number = '4111-1111-4555-1142'
+    card_translation = str.maketrans({'-': '', ' ': ''})
+    translated_card_number = card_number.translate(card_translation)
+
+    verify_card_number(translated_card_number)
+
+main()
+```
@@ -0,0 +1,48 @@
+---
+id: 65687a923dd792ad339f9c09
+title: Step 18
+challengeType: 20
+dashedName: step-18
+---
+
+# --description--
+
+Print the value of the `odd_digits` variable to the console.
+
+# --hints--
+
+You should have `print(odd_digits)` within the `verify_card_number` function.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const verify_card_number = __helpers.python.getDef("\n" + transformedCode, "verify_card_number");
+        const { function_body } = verify_card_number;
+
+        assert.match(function_body, /print\(\s*odd_digits\s*\)/);
+    }
+})
+```
+
+# --seed--
+
+## --seed-contents--
+
+```py
+--fcc-editable-region--
+def verify_card_number(card_number):
+    sum_of_odd_digits = 0
+    card_number_reversed = card_number[::-1]
+    odd_digits = card_number_reversed[::2]
+    
+--fcc-editable-region--
+def main():
+    card_number = '4111-1111-4555-1142'
+    card_translation = str.maketrans({'-': '', ' ': ''})
+    translated_card_number = card_number.translate(card_translation)
+
+    verify_card_number(translated_card_number)
+
+main()
+```
@@ -0,0 +1,68 @@
+---
+id: 65687ad86596e0af38640a84
+title: Step 19
+challengeType: 20
+dashedName: step-19
+---
+
+# --description--
+
+Use a `for` loop to iterate over each digit in the `odd_digits` list. Move your `print` call from the previous step into the `for` loop, and change it to print each digit.
+
+# --hints--
+
+You should use a `for` loop over `odd_digits`.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const verify_card_number = __helpers.python.getDef("\n" + transformedCode, "verify_card_number");
+        const { function_body } = verify_card_number;
+
+        assert.match(function_body, /for\s+\w+\s+in\s+odd_digits/);
+    }
+})
+```
+
+You should have `--fcc-expected--` within the `for` loop.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const verify_card_number = __helpers.python.getDef("\n" + transformedCode, "verify_card_number");
+        const { function_body } = verify_card_number;
+    
+        // Get variable name used in for loop
+        const for_loop_variable = function_body.match(/for\s+(\w+)\s+in\s+odd_digits/)?.[1];
+        assert.exists(for_loop_variable);
+
+        assert.equal(function_body.match(new RegExp(`print\\(\\s*${for_loop_variable}\\s*\\)`))?.[0], `print(${for_loop_variable})`);
+    }
+})
+```
+
+# --seed--
+
+## --seed-contents--
+
+```py
+--fcc-editable-region--
+def verify_card_number(card_number):
+    sum_of_odd_digits = 0
+    card_number_reversed = card_number[::-1]
+    odd_digits = card_number_reversed[::2]
+
+    print(odd_digits)
+    
+--fcc-editable-region--
+def main():
+    card_number = '4111-1111-4555-1142'
+    card_translation = str.maketrans({'-': '', ' ': ''})
+    translated_card_number = card_number.translate(card_translation)
+
+    verify_card_number(translated_card_number)
+
+main()
+```
@@ -0,0 +1,47 @@
+---
+id: 65687b182c2a8fb1470e0b97
+title: Step 20
+challengeType: 20
+dashedName: step-20
+---
+
+# --description--
+
+Within the `for` loop, use the `+=` operator to add the `digit` to the `sum_of_odd_digits` variable.
+
+# --hints--
+
+You should have `sum_of_odd_digits += digit` within the `for` loop.
+
+```js
+const transformedCode = code.replace(/\r/g, "");
+const verify_card_number = __helpers.python.getDef("\n" + transformedCode, "verify_card_number");
+const { function_body } = verify_card_number;
+
+assert.match(function_body, /sum_of_odd_digits\s*\+=\s*digit/);
+```
+
+# --seed--
+
+## --seed-contents--
+
+```py
+--fcc-editable-region--
+def verify_card_number(card_number):
+    sum_of_odd_digits = 0
+    card_number_reversed = card_number[::-1]
+    odd_digits = card_number_reversed[::2]
+
+    for digit in odd_digits:
+        print(digit)
+        
+--fcc-editable-region--
+def main():
+    card_number = '4111-1111-4555-1142'
+    card_translation = str.maketrans({'-': '', ' ': ''})
+    translated_card_number = card_number.translate(card_translation)
+
+    verify_card_number(translated_card_number)
+
+main()
+```
@@ -0,0 +1,89 @@
+---
+id: 65687b48f2201ab32e06c37c
+title: Step 21
+challengeType: 20
+dashedName: step-21
+---
+
+# --description--
+
+Currently, your script throws a `TypeError` because you are trying to add a string to an integer. You can fix this by converting the `digit` variable to an integer before adding it to `sum_of_odd_digits`, using the built-in `int` function:
+
+```python
+my_string = '123'
+my_int = int(my_string)
+```
+
+Convert the `digit` variable to an integer before adding it to `sum_of_odd_digits`. Then, move the `print` call to the end of the `verify_card_number` function to print the value of `sum_of_odd_digits`.
+
+# --hints--
+
+You should have `sum_of_odd_digits += int(digit)` within the `for` loop.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const verify_card_number = __helpers.python.getDef("\n" + transformedCode, "verify_card_number");
+        const { function_body } = verify_card_number;
+
+        assert.match(function_body, /sum_of_odd_digits\s*\+=\s*int\(digit\)/);
+    }
+})
+```
+
+You should have `print(sum_of_odd_digits)` at the end of the `verify_card_number` function.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const verify_card_number = __helpers.python.getDef("\n" + transformedCode, "verify_card_number");
+        const { function_body } = verify_card_number;
+
+        assert.match(function_body, /print\(\s*sum_of_odd_digits\s*\)/);
+    }
+})
+```
+
+You should not have `print(digit)` anymore.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const verify_card_number = __helpers.python.getDef("\n" + transformedCode, "verify_card_number");
+        const { function_body } = verify_card_number;
+
+        const no_comments = __helpers.python.removeComments(function_body);
+
+        assert.notMatch(no_comments, /print\(\s*digit\s*\)/);
+    }
+})
+```
+
+# --seed--
+
+## --seed-contents--
+
+```py
+def verify_card_number(card_number):
+    sum_of_odd_digits = 0
+    card_number_reversed = card_number[::-1]
+    odd_digits = card_number_reversed[::2]
+
+--fcc-editable-region--
+    for digit in odd_digits:
+        print(digit)
+        sum_of_odd_digits += digit
+        
+--fcc-editable-region--
+def main():
+    card_number = '4111-1111-4555-1142'
+    card_translation = str.maketrans({'-': '', ' ': ''})
+    translated_card_number = card_number.translate(card_translation)
+
+    verify_card_number(translated_card_number)
+
+main()
+```
@@ -0,0 +1,52 @@
+---
+id: 65687b68003a61b46fe691f0
+title: Step 22
+challengeType: 20
+dashedName: step-22
+---
+
+# --description--
+
+Below your `print` call, create a variable named `sum_of_even_digits` and assign it a value of `0`.
+
+# --hints--
+
+You should have `sum_of_even_digits = 0` below your `print` call.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const verify_card_number = __helpers.python.getDef("\n" + transformedCode, "verify_card_number");
+        const { function_body } = verify_card_number;
+
+        assert.match(function_body, /sum_of_even_digits\s*=\s*0/);
+    }
+})
+```
+
+# --seed--
+
+## --seed-contents--
+
+```py
+--fcc-editable-region--
+def verify_card_number(card_number):
+    sum_of_odd_digits = 0
+    card_number_reversed = card_number[::-1]
+    odd_digits = card_number_reversed[::2]
+
+    for digit in odd_digits:
+        sum_of_odd_digits += int(digit)
+    print(sum_of_odd_digits)
+    
+--fcc-editable-region--
+def main():
+    card_number = '4111-1111-4555-1142'
+    card_translation = str.maketrans({'-': '', ' ': ''})
+    translated_card_number = card_number.translate(card_translation)
+
+    verify_card_number(translated_card_number)
+
+main()
+```
@@ -0,0 +1,54 @@
+---
+id: 65687b8eb0bbf7b5d41b610b
+title: Step 23
+challengeType: 20
+dashedName: step-23
+---
+
+# --description--
+
+Create a variable `even_digits` and assign it the even digits of the reversed card number.
+
+# --hints--
+
+You should have `even_digits = card_number_reversed[1::2]` within the `verify_card_number` function.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const verify_card_number = __helpers.python.getDef("\n" + transformedCode, "verify_card_number");
+        const { function_body } = verify_card_number;
+
+        assert.match(function_body, /even_digits\s*=\s*card_number_reversed\[1::2\]/);
+    }
+})
+```
+
+# --seed--
+
+## --seed-contents--
+
+```py
+def verify_card_number(card_number):
+    sum_of_odd_digits = 0
+    card_number_reversed = card_number[::-1]
+    odd_digits = card_number_reversed[::2]
+
+    for digit in odd_digits:
+        sum_of_odd_digits += int(digit)
+    print(sum_of_odd_digits)
+
+--fcc-editable-region--
+    sum_of_even_digits = 0
+    
+--fcc-editable-region--
+def main():
+    card_number = '4111-1111-4555-1142'
+    card_translation = str.maketrans({'-': '', ' ': ''})
+    translated_card_number = card_number.translate(card_translation)
+
+    verify_card_number(translated_card_number)
+
+main()
+```
@@ -0,0 +1,75 @@
+---
+id: 65687bbfd9a7d6b78cd5b5cf
+title: Step 24
+challengeType: 20
+dashedName: step-24
+---
+
+# --description--
+
+Loop over the even digits and print each to the console.
+
+# --hints--
+
+You should have a `for` loop over `even_digits` within the `verify_card_number` function.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const verify_card_number = __helpers.python.getDef("\n" + transformedCode, "verify_card_number");
+        const { function_body } = verify_card_number;
+
+        assert.match(function_body, /for +(\w+) +in +even_digits:/);
+    }
+})
+```
+
+You should have `--fcc-expected--` within the `for` loop.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const verify_card_number = __helpers.python.getDef("\n" + transformedCode, "verify_card_number");
+        const { function_body } = verify_card_number;
+
+        // Get the name of the variable used in the for loop
+        const for_loop_variable = function_body.match(/for +(\w+) +in +even_digits:/)?.[1];
+        assert.exists(for_loop_variable);
+
+        const [_,lower_function_body] = function_body.split("sum_of_even_digits");
+
+        assert.equal(lower_function_body.match(new RegExp(`print\\(\\s*${for_loop_variable}\\s*\\)`))?.[0], `print(${for_loop_variable})`);
+    }
+})
+```
+
+# --seed--
+
+## --seed-contents--
+
+```py
+def verify_card_number(card_number):
+    sum_of_odd_digits = 0
+    card_number_reversed = card_number[::-1]
+    odd_digits = card_number_reversed[::2]
+
+    for digit in odd_digits:
+        sum_of_odd_digits += int(digit)
+    print(sum_of_odd_digits)
+
+--fcc-editable-region--
+    sum_of_even_digits = 0
+    even_digits = card_number_reversed[1::2]
+    
+--fcc-editable-region--
+def main():
+    card_number = '4111-1111-4555-1142'
+    card_translation = str.maketrans({'-': '', ' ': ''})
+    translated_card_number = card_number.translate(card_translation)
+
+    verify_card_number(translated_card_number)
+
+main()
+```
@@ -0,0 +1,56 @@
+---
+id: 65687c2fd0fec7ba9fb8af30
+title: Step 25
+challengeType: 20
+dashedName: step-25
+---
+
+# --description--
+
+Remove the `print` call for the sum of the odd digits.
+
+# --hints--
+
+You should not have `print(sum_of_odd_digits)` in your code.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const verify_card_number = __helpers.python.getDef("\n" + transformedCode, "verify_card_number");
+        const { function_body } = verify_card_number;
+        const no_comments = __helpers.python.removeComments(function_body);
+        assert.notMatch(no_comments, /print\(\s*sum_of_odd_digits\s*\)/);
+    }
+})
+```
+
+# --seed--
+
+## --seed-contents--
+
+```py
+--fcc-editable-region--
+def verify_card_number(card_number):
+    sum_of_odd_digits = 0
+    card_number_reversed = card_number[::-1]
+    odd_digits = card_number_reversed[::2]
+
+    for digit in odd_digits:
+        sum_of_odd_digits += int(digit)
+    print(sum_of_odd_digits)
+
+    sum_of_even_digits = 0
+    even_digits = card_number_reversed[1::2]
+    for digit in even_digits:
+        print(digit)
+--fcc-editable-region--
+def main():
+    card_number = '4111-1111-4555-1142'
+    card_translation = str.maketrans({'-': '', ' ': ''})
+    translated_card_number = card_number.translate(card_translation)
+
+    verify_card_number(translated_card_number)
+
+main()
+```
@@ -0,0 +1,73 @@
+---
+id: 65687c8d86e18cbd775a53c9
+title: Step 26
+challengeType: 20
+dashedName: step-26
+---
+
+# --description--
+
+The next part of the Luhn Algorithm is to multiply all the even digits by `2`.
+
+Within the even digit `for` loop, replace the `print` call with a variable named `number` and assign it the value of `digit` multiplied by `2`.
+
+# --hints--
+
+You should have `number = int(digit) * 2` within the `for` loop.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const verify_card_number = __helpers.python.getDef("\n" + transformedCode, "verify_card_number");
+        const { function_body } = verify_card_number;
+
+        assert.match(function_body, /number\s*=\s*int\(digit\)\s*\*\s*2/);
+    }
+})
+```
+
+You should not have `print(digit)` within the `for` loop.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const verify_card_number = __helpers.python.getDef("\n" + transformedCode, "verify_card_number");
+        const { function_body } = verify_card_number;
+
+        const no_comments = __helpers.python.removeComments(function_body);
+
+        assert.notMatch(no_comments, /print\s*\(\s*digit\s*\)/);
+    }
+})
+```
+
+# --seed--
+
+## --seed-contents--
+
+```py
+def verify_card_number(card_number):
+    sum_of_odd_digits = 0
+    card_number_reversed = card_number[::-1]
+    odd_digits = card_number_reversed[::2]
+
+    for digit in odd_digits:
+        sum_of_odd_digits += int(digit)
+
+--fcc-editable-region--
+    sum_of_even_digits = 0
+    even_digits = card_number_reversed[1::2]
+    for digit in even_digits:
+        print(digit)
+--fcc-editable-region--
+def main():
+    card_number = '4111-1111-4555-1142'
+    card_translation = str.maketrans({'-': '', ' ': ''})
+    translated_card_number = card_number.translate(card_translation)
+
+    verify_card_number(translated_card_number)
+
+main()
+```
@@ -0,0 +1,72 @@
+---
+id: 65687da2e60409c45595bbe1
+title: Step 27
+challengeType: 20
+dashedName: step-27
+---
+
+# --description--
+
+To prevent the multiplication of one digit from being greater than `9`, within the even digit loop, add an `if` statement that checks if `number` is greater than or equal to `10`. If it is, print `number`.
+
+# --hints--
+
+You should have `if number >= 10:` within the `for` loop.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const verify_card_number = __helpers.python.getDef("\n" + transformedCode, "verify_card_number");
+        const { function_body } = verify_card_number;
+
+        assert.match(function_body, /if +number +>= +10:/);
+    }
+})
+```
+
+You should have `print(number)` within the `if` statement.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const verify_card_number = __helpers.python.getDef("\n" + transformedCode, "verify_card_number");
+        const { function_body } = verify_card_number;
+
+        const [_,lower_function_body] = function_body.split("sum_of_even_digits");
+
+        assert.match(lower_function_body, /print\s*\(\s*number\s*\)/);
+    }
+})
+```
+
+# --seed--
+
+## --seed-contents--
+
+```py
+def verify_card_number(card_number):
+    sum_of_odd_digits = 0
+    card_number_reversed = card_number[::-1]
+    odd_digits = card_number_reversed[::2]
+
+    for digit in odd_digits:
+        sum_of_odd_digits += int(digit)
+
+--fcc-editable-region--
+    sum_of_even_digits = 0
+    even_digits = card_number_reversed[1::2]
+    for digit in even_digits:
+        number = int(digit) * 2
+        
+--fcc-editable-region--
+def main():
+    card_number = '4111-1111-4555-1142'
+    card_translation = str.maketrans({'-': '', ' ': ''})
+    translated_card_number = card_number.translate(card_translation)
+
+    verify_card_number(translated_card_number)
+
+main()
+```
@@ -0,0 +1,73 @@
+---
+id: 65687db6a9fcf3c548a6c1b7
+title: Step 28
+challengeType: 20
+dashedName: step-28
+---
+
+# --description--
+
+Part of the algorithm is to double every second digit, starting from the right. If the result of doubling the number is greater than or equal to `10`, add the two digits together. For example, if the digit is `6`, double it to get `12`. Add `1` and `2` together to get `3`. You can do this by using _integer division_ to get the first digit and the modulus operator (`%`) to get the second digit:
+
+```python
+my_number = 12
+first_digit = my_number // 10
+second_digit = my_number % 10
+```
+
+Integer division results in the quotient of the division, rounded down to the nearest integer.
+
+Within the `if` statement, assign `number` the result of `number // 10` (integer division) plus the modulus of `number` and `10`.
+
+# --hints--
+
+You should have `number = number // 10 + number % 10` within the `if` statement.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const verify_card_number = __helpers.python.getBlock("\n" + transformedCode, "if number >= 10");
+        const { block_body } = verify_card_number;
+        const allowedMatches = [
+            /number *= *\(?number *\/\/ *10\)? *\+ *\(?number *% *10/,
+            /number *= *\(?number *% *10\)? *\+ *\(?number *\/\/ *10/
+        ];
+
+        const someMatch = allowedMatches.some(allowedMatch => allowedMatch.test(block_body));
+        assert.isTrue(someMatch);
+    }
+})
+```
+
+# --seed--
+
+## --seed-contents--
+
+```py
+def verify_card_number(card_number):
+    sum_of_odd_digits = 0
+    card_number_reversed = card_number[::-1]
+    odd_digits = card_number_reversed[::2]
+
+    for digit in odd_digits:
+        sum_of_odd_digits += int(digit)
+
+--fcc-editable-region--
+    sum_of_even_digits = 0
+    even_digits = card_number_reversed[1::2]
+    for digit in even_digits:
+        number = int(digit) * 2
+        if number >= 10:
+            print(number)
+            
+--fcc-editable-region--
+def main():
+    card_number = '4111-1111-4555-1142'
+    card_translation = str.maketrans({'-': '', ' ': ''})
+    translated_card_number = card_number.translate(card_translation)
+
+    verify_card_number(translated_card_number)
+
+main()
+```
@@ -0,0 +1,61 @@
+---
+id: 65687dd4b641fdc67d7de487
+title: Step 29
+challengeType: 20
+dashedName: step-29
+---
+
+# --description--
+
+Move the `print` call below the `number` reassignment.
+
+# --hints--
+
+You should move `print(number)` below `number = (number // 10) + (number % 10)`.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const if_statement = __helpers.python.getBlock("\n" + transformedCode, "if number >= 10");
+
+        const { block_body } = if_statement;
+        const [number_assignment, print_pos] = block_body.split('\n').filter(line => line.trim().length > 0);
+        assert.match(number_assignment, /number *=/);
+        assert.match(print_pos, /print\s*\(\s*number\s*\)/);
+    }
+})
+```
+
+# --seed--
+
+## --seed-contents--
+
+```py
+def verify_card_number(card_number):
+    sum_of_odd_digits = 0
+    card_number_reversed = card_number[::-1]
+    odd_digits = card_number_reversed[::2]
+
+    for digit in odd_digits:
+        sum_of_odd_digits += int(digit)
+
+--fcc-editable-region--
+    sum_of_even_digits = 0
+    even_digits = card_number_reversed[1::2]
+    for digit in even_digits:
+        number = int(digit) * 2
+        if number >= 10:
+            print(number)
+            number = (number // 10) + (number % 10)
+            
+--fcc-editable-region--
+def main():
+    card_number = '4111-1111-4555-1142'
+    card_translation = str.maketrans({'-': '', ' ': ''})
+    translated_card_number = card_number.translate(card_translation)
+
+    verify_card_number(translated_card_number)
+
+main()
+```
@@ -0,0 +1,89 @@
+---
+id: 65687e069cf4e0c85b0a06b1
+title: Step 30
+challengeType: 20
+dashedName: step-30
+---
+
+# --description--
+
+Outside of the `if` statement, add `number` to `sum_of_even_digits`. Also, remove the `print` call.
+
+# --hints--
+
+You should have `sum_of_even_digits += number` within the `for` loop.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const for_loop = __helpers.python.getBlock("\n" + transformedCode, "for digit in even_digits");
+        const {block_body} = for_loop;
+
+        assert.match(block_body, /sum_of_even_digits\s*\+=\s*number/);
+    }
+})
+```
+
+You should not have `print(number)` within the `for` loop.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const verify_card_number = __helpers.python.getDef("\n" + transformedCode, "verify_card_number");
+        const { function_body } = verify_card_number;
+
+        const no_comments = __helpers.python.removeComments(function_body);
+
+        assert.notMatch(no_comments, /print\s*\(\s*number\s*\)/);
+    }
+})
+```
+
+You should not have `sum_of_even_digits += number` within the `if` statement.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const if_statement = __helpers.python.getBlock("\n" + transformedCode, "if number >= 10");
+        const {block_body} = if_statement;
+
+        assert.notMatch(block_body, /sum_of_even_digits *\+= *number/);
+    }
+})
+```
+
+# --seed--
+
+## --seed-contents--
+
+```py
+def verify_card_number(card_number):
+    sum_of_odd_digits = 0
+    card_number_reversed = card_number[::-1]
+    odd_digits = card_number_reversed[::2]
+
+    for digit in odd_digits:
+        sum_of_odd_digits += int(digit)
+
+--fcc-editable-region--
+    sum_of_even_digits = 0
+    even_digits = card_number_reversed[1::2]
+    for digit in even_digits:
+        number = int(digit) * 2
+        if number >= 10:
+            number = (number // 10) + (number % 10)
+            print(number)
+        
+--fcc-editable-region--
+def main():
+    card_number = '4111-1111-4555-1142'
+    card_translation = str.maketrans({'-': '', ' ': ''})
+    translated_card_number = card_number.translate(card_translation)
+
+    verify_card_number(translated_card_number)
+
+main()
+```
@@ -0,0 +1,77 @@
+---
+id: 65687e0ed12e20c91811a48d
+title: Step 31
+challengeType: 20
+dashedName: step-31
+---
+
+# --description--
+
+Below the second `for` loop of the `verify_card_number` function, create a variable named `total`, and assign it the value of the sum of the odd and even digits. Print `total` to the console.
+
+# --hints--
+
+You should have `total = sum_of_odd_digits + sum_of_even_digits` within the `verify_card_number` function.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const verify_card_number = __helpers.python.getDef("\n" + transformedCode, "verify_card_number");
+        const { function_body } = verify_card_number;
+
+        const function_body_indentation = function_body.match(/^\s*/)[0];
+
+        const total_re = new RegExp(`^${function_body_indentation}total\\s*=\\s*sum_of_odd_digits\\s*\\+\\s*sum_of_even_digits`, "m");
+
+        assert.match(function_body, total_re);
+    }
+})
+```
+
+You should have `print(total)` within the `verify_card_number` function.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const verify_card_number = __helpers.python.getDef("\n" + transformedCode, "verify_card_number");
+        const { function_body } = verify_card_number;
+
+        assert.match(function_body, /print\(\s*total\s*\)/);
+    }
+})
+```
+
+# --seed--
+
+## --seed-contents--
+
+```py
+def verify_card_number(card_number):
+    sum_of_odd_digits = 0
+    card_number_reversed = card_number[::-1]
+    odd_digits = card_number_reversed[::2]
+
+    for digit in odd_digits:
+        sum_of_odd_digits += int(digit)
+
+--fcc-editable-region--
+    sum_of_even_digits = 0
+    even_digits = card_number_reversed[1::2]
+    for digit in even_digits:
+        number = int(digit) * 2
+        if number >= 10:
+            number = (number // 10) + (number % 10)
+        sum_of_even_digits += number
+    
+--fcc-editable-region--
+def main():
+    card_number = '4111-1111-4555-1142'
+    card_translation = str.maketrans({'-': '', ' ': ''})
+    translated_card_number = card_number.translate(card_translation)
+
+    verify_card_number(translated_card_number)
+
+main()
+```
@@ -0,0 +1,70 @@
+---
+id: 65687e294ef2bdca637fb213
+title: Step 32
+challengeType: 20
+dashedName: step-32
+---
+
+# --description--
+
+Return the result of comparing `0` to `total` modulo `10`.
+
+# --hints--
+
+You should have `return 0 == total % 10` within the `verify_card_number` function.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const verify_card_number = __helpers.python.getDef("\n" + transformedCode, "verify_card_number");
+        const { function_body } = verify_card_number;
+
+        const acceptableMatches = [
+            /return +0 *== *total *% *10/,
+            /return +total *% *10 *== *0/
+        ];
+
+        const someMatch = acceptableMatches.some((match) => {
+            return match.test(function_body);
+        });
+
+        assert.isTrue(someMatch);
+    }
+})
+```
+
+# --seed--
+
+## --seed-contents--
+
+```py
+def verify_card_number(card_number):
+    sum_of_odd_digits = 0
+    card_number_reversed = card_number[::-1]
+    odd_digits = card_number_reversed[::2]
+
+    for digit in odd_digits:
+        sum_of_odd_digits += int(digit)
+
+    sum_of_even_digits = 0
+    even_digits = card_number_reversed[1::2]
+    for digit in even_digits:
+        number = int(digit) * 2
+        if number >= 10:
+            number = (number // 10) + (number % 10)
+        sum_of_even_digits += number
+--fcc-editable-region--
+    total = sum_of_odd_digits + sum_of_even_digits
+    print(total)
+
+--fcc-editable-region--
+def main():
+    card_number = '4111-1111-4555-1142'
+    card_translation = str.maketrans({'-': '', ' ': ''})
+    translated_card_number = card_number.translate(card_translation)
+
+    verify_card_number(translated_card_number)
+
+main()
+```
@@ -0,0 +1,90 @@
+---
+id: 65687e457ab1c4cb8c3fe7c8
+title: Step 33
+challengeType: 20
+dashedName: step-33
+---
+
+# --description--
+
+Adjust the `verify_card_number` call such that if it returns `True`, print `VALID!` to the console. Otherwise, print `INVALID!`.
+
+# --hints--
+
+You should have `if verify_card_number(translated_card_number):` within the `main` function.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const main = __helpers.python.getDef("\n" + transformedCode, "main");
+        const { function_body } = main;
+        
+        const if_statement = __helpers.python.getBlock("\n" + function_body, "if verify_card_number(translated_card_number)");
+        assert.exists(if_statement);
+    }
+})
+```
+
+You should have `print("VALID!")` within the `if` statement.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const if_statement = __helpers.python.getBlock("\n" + transformedCode, "if verify_card_number(translated_card_number)");
+        const {block_body} = if_statement;
+
+        assert.match(block_body, /print\(\s*('|")VALID!\1\s*\)/);
+    }
+})
+```
+
+You should have `print("INVALID!")` within the `else` clause.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const else_statement = __helpers.python.getBlock("\n" + transformedCode, "else");
+        const {block_body} = else_statement;
+
+        assert.match(block_body, /print\(\s*('|")INVALID!\1\s*\)/);
+    }
+})
+```
+
+# --seed--
+
+## --seed-contents--
+
+```py
+def verify_card_number(card_number):
+    sum_of_odd_digits = 0
+    card_number_reversed = card_number[::-1]
+    odd_digits = card_number_reversed[::2]
+
+    for digit in odd_digits:
+        sum_of_odd_digits += int(digit)
+
+    sum_of_even_digits = 0
+    even_digits = card_number_reversed[1::2]
+    for digit in even_digits:
+        number = int(digit) * 2
+        if number >= 10:
+            number = (number // 10) + (number % 10)
+        sum_of_even_digits += number
+    total = sum_of_odd_digits + sum_of_even_digits
+    print(total)
+    return total % 10 == 0
+--fcc-editable-region--
+def main():
+    card_number = '4111-1111-4555-1142'
+    card_translation = str.maketrans({'-': '', ' ': ''})
+    translated_card_number = card_number.translate(card_translation)
+
+    verify_card_number(translated_card_number)
+--fcc-editable-region--
+
+main()
+```
@@ -0,0 +1,62 @@
+---
+id: 65687f47f9001dd35bdcd5ab
+title: Step 34
+challengeType: 20
+dashedName: step-34
+---
+
+# --description--
+
+Change the value of `card_number` such that `INVALID!` is printed to the console.
+
+# --hints--
+
+You could have `card_number = '4111-1111-4555-1141'` within the main function.
+
+```js
+({
+  test: () => {
+    const spyCode = "a = ''\ndef printSpy(*x):\n    global a\n    a += str(x)\n" + code.replaceAll("print(", "printSpy(") + "\na";
+    const out = __pyodide.runPython(spyCode);
+    assert.include(out, "INVALID!");
+  }
+})
+```
+
+# --seed--
+
+## --seed-contents--
+
+```py
+def verify_card_number(card_number):
+    sum_of_odd_digits = 0
+    card_number_reversed = card_number[::-1]
+    odd_digits = card_number_reversed[::2]
+
+    for digit in odd_digits:
+        sum_of_odd_digits += int(digit)
+
+    sum_of_even_digits = 0
+    even_digits = card_number_reversed[1::2]
+    for digit in even_digits:
+        number = int(digit) * 2
+        if number >= 10:
+            number = (number // 10) + (number % 10)
+        sum_of_even_digits += number
+    total = sum_of_odd_digits + sum_of_even_digits
+    print(total)
+    return total % 10 == 0
+--fcc-editable-region--
+def main():
+    card_number = '4111-1111-4555-1142'
+    card_translation = str.maketrans({'-': '', ' ': ''})
+    translated_card_number = card_number.translate(card_translation)
+--fcc-editable-region--
+
+    if verify_card_number(translated_card_number):
+        print('VALID!')
+    else:
+        print('INVALID!')
+
+main()
+```
@@ -0,0 +1,115 @@
+---
+id: 656880227dab4bd8fbc02d41
+title: Step 35
+challengeType: 20
+dashedName: step-35
+---
+
+# --description--
+
+Well done on completing this project.
+
+As a final step, remove the `print` call from the `verify_card_number` function, and change the `card_number` back to something valid.
+
+# --hints--
+
+You should not have a `print` call within the `verify_card_number` function.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const verify_card_number = __helpers.python.getDef("\n" + transformedCode, "verify_card_number");
+        const { function_body } = verify_card_number;
+        const no_comments = __helpers.python.removeComments(function_body);
+        assert.notMatch(no_comments, /print\(/);
+    }
+})
+```
+
+You should change `card_number` back to something valid.
+
+```js
+({
+    test: () => {
+        const spyCode = "a = ''\ndef printSpy(*x):\n    global a\n    a = str(x)\n" + code.replaceAll("print(", "printSpy(") + "\na";
+        const out = __pyodide.runPython(spyCode);
+        assert.notInclude(out, "INVALID!");
+        assert.include(out, "VALID!");
+    }
+})
+```
+
+# --seed--
+
+## --seed-contents--
+
+```py
+--fcc-editable-region--
+def verify_card_number(card_number):
+    sum_of_odd_digits = 0
+    card_number_reversed = card_number[::-1]
+    odd_digits = card_number_reversed[::2]
+
+    for digit in odd_digits:
+        sum_of_odd_digits += int(digit)
+
+    sum_of_even_digits = 0
+    even_digits = card_number_reversed[1::2]
+    for digit in even_digits:
+        number = int(digit) * 2
+        if number >= 10:
+            number = (number // 10) + (number % 10)
+        sum_of_even_digits += number
+    total = sum_of_odd_digits + sum_of_even_digits
+    print(total)
+    return total % 10 == 0
+
+def main():
+    card_number = '4111-1111-4555-1141'
+    card_translation = str.maketrans({'-': '', ' ': ''})
+    translated_card_number = card_number.translate(card_translation)
+
+    if verify_card_number(translated_card_number):
+        print('VALID!')
+    else:
+        print('INVALID!')
+
+main()
+--fcc-editable-region--
+```
+
+# --solutions--
+
+```py
+def verify_card_number(card_number):
+    sum_of_odd_digits = 0
+    card_number_reversed = card_number[::-1]
+    odd_digits = card_number_reversed[::2]
+
+    for digit in odd_digits:
+        sum_of_odd_digits += int(digit)
+
+    sum_of_even_digits = 0
+    even_digits = card_number_reversed[1::2]
+    for digit in even_digits:
+        number = int(digit) * 2
+        if number >= 10:
+            number = (number // 10) + (number % 10)
+        sum_of_even_digits += number
+
+    total = sum_of_odd_digits + sum_of_even_digits
+    return total % 10 == 0
+
+def main():
+    card_number = '4111-1111-4555-1142'
+    card_translation = str.maketrans({'-': '', ' ': ''})
+    translated_card_number = card_number.translate(card_translation)
+
+    if verify_card_number(translated_card_number):
+        print('VALID!')
+    else:
+        print('INVALID!')
+
+main()
+```
@@ -0,0 +1,59 @@
+---
+id: 6569b831a07d7154c793301b
+title: Step 7
+challengeType: 20
+dashedName: step-7
+---
+
+# --description--
+
+Define a function `verify_card_number` with a parameter `card_number`, and use the `pass` keyword to make the function do nothing.
+
+# --hints--
+
+You should have a function called `verify_card_number` with a parameter called `card_number`.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const verify_card_number = __helpers.python.getDef("\n" + transformedCode, "verify_card_number");
+        assert.exists(verify_card_number);
+        const { function_parameters } = verify_card_number;
+        assert.equal(function_parameters.trim(), "card_number");
+    }
+})
+```
+
+You should use the `pass` keyword in the body of the `verify_card_number` function.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const verify_card_number = __helpers.python.getDef("\n" + transformedCode, "verify_card_number");
+        assert.exists(verify_card_number);
+        const { function_body } = verify_card_number;
+        assert.match(function_body, / +pass/);
+    }
+})
+```
+
+# --seed--
+
+## --seed-contents--
+
+```py
+--fcc-editable-region--
+
+--fcc-editable-region--
+
+def main():
+    card_number = '4111-1111-4555-1142'
+    card_translation = str.maketrans({'-': '', ' ': ''})
+    translated_card_number = card_number.translate(card_translation)
+
+    print(translated_card_number)
+
+main()
+```
@@ -0,0 +1,49 @@
+---
+id: 656b4638cb8bcf2729afe9a9
+title: Step 11
+challengeType: 20
+dashedName: step-11
+---
+
+# --description--
+
+Print the value of the `card_number_reversed` variable to the console.
+
+# --hints--
+
+You should have `print(card_number_reversed)` within the `verify_card_number` function.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const verify_card_number = __helpers.python.getDef("\n" + transformedCode, "verify_card_number");
+        const { function_body } = verify_card_number;
+
+        assert.match(function_body, /print\(\s*card_number_reversed\s*\)/);
+    }
+})
+```
+
+# --seed--
+
+## --seed-contents--
+
+```py
+--fcc-editable-region--
+def verify_card_number(card_number):
+    sum_of_odd_digits = 0
+    card_number_reversed = card_number[0:4]
+    
+--fcc-editable-region--
+def main():
+    card_number = '4111-1111-4555-1142'
+    card_translation = str.maketrans({'-': '', ' ': ''})
+    translated_card_number = card_number.translate(card_translation)
+
+    print(translated_card_number)
+
+    verify_card_number(translated_card_number)
+
+main()
+```
@@ -0,0 +1,50 @@
+---
+id: 656b475b394390334828eb12
+title: Step 12
+challengeType: 20
+dashedName: step-12
+---
+
+# --description--
+
+Change `card_number_reversed` to be every second digit of the first four digits of `card_number`.
+
+# --hints--
+
+You should have `card_number_reversed = card_number[0:4:2]` within the `verify_card_number` function.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const verify_card_number = __helpers.python.getDef("\n" + transformedCode, "verify_card_number");
+        const { function_body } = verify_card_number;
+
+        assert.match(function_body, /card_number_reversed\s*=\s*card_number\[0:4:2\]/);
+    }
+})
+```
+
+# --seed--
+
+## --seed-contents--
+
+```py
+--fcc-editable-region--
+def verify_card_number(card_number):
+    sum_of_odd_digits = 0
+    card_number_reversed = card_number[0:4]
+    print(card_number_reversed)
+    
+--fcc-editable-region--
+def main():
+    card_number = '4111-1111-4555-1142'
+    card_translation = str.maketrans({'-': '', ' ': ''})
+    translated_card_number = card_number.translate(card_translation)
+
+    print(translated_card_number)
+
+    verify_card_number(translated_card_number)
+
+main()
+```
@@ -0,0 +1,58 @@
+---
+id: 656b47dc2cf39e37025dc033
+title: Step 13
+challengeType: 20
+dashedName: step-13
+---
+
+# --description--
+
+Reverse the order of the digits in the last four digits of `card_number`, by using a slice with a step of `-1`. You can use either negative or positive indices for the start and end indices.
+
+# --hints--
+
+You could have `card_number_reversed = card_number[-1:-5:-1]` within the `verify_card_number` function. Expected `--fcc-actual--` to equal `--fcc-expected--`.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const verify_card_number = __helpers.python.getDef("\n" + transformedCode, "verify_card_number");
+        const { function_body, def } = verify_card_number;
+
+        const pyCode = `
+card_number = "4111111145551142"
+${def}
+${function_body.match(/ +/)[0]}return card_number_reversed
+
+verify_card_number(card_number)
+`;
+        const out = __pyodide.runPython(pyCode, {});
+        assert.equal(out, "2411");
+    }
+})
+```
+
+# --seed--
+
+## --seed-contents--
+
+```py
+--fcc-editable-region--
+def verify_card_number(card_number):
+    sum_of_odd_digits = 0
+    card_number_reversed = card_number[0:4:2]
+    print(card_number_reversed)
+    
+--fcc-editable-region--
+def main():
+    card_number = '4111-1111-4555-1142'
+    card_translation = str.maketrans({'-': '', ' ': ''})
+    translated_card_number = card_number.translate(card_translation)
+
+    print(translated_card_number)
+
+    verify_card_number(translated_card_number)
+
+main()
+```
@@ -0,0 +1,57 @@
+---
+id: 656b481ec4976439565a78b2
+title: Step 14
+challengeType: 20
+dashedName: step-14
+---
+
+# --description--
+
+Just as the step is optional, a start at `0` and an end at the end of the slice are optional:
+
+```python
+my_string = 'camperbot'
+camperbot = my_string[::]
+```
+
+Assign the reverse of the full `card_number` string to the `card_number_reversed` variable.
+
+# --hints--
+
+You should have `card_number_reversed = card_number[::-1]` within the `verify_card_number` function.
+
+```js
+({
+    test: () => {
+        const transformedCode = code.replace(/\r/g, "");
+        const verify_card_number = __helpers.python.getDef("\n" + transformedCode, "verify_card_number");
+        const { function_body } = verify_card_number;
+
+        assert.match(function_body, /card_number_reversed\s*=\s*card_number\[::-1\]/);
+    }
+})
+```
+
+# --seed--
+
+## --seed-contents--
+
+```py
+--fcc-editable-region--
+def verify_card_number(card_number):
+    sum_of_odd_digits = 0
+    card_number_reversed = card_number[-1:-5:-1]
+    print(card_number_reversed)
+    
+--fcc-editable-region--
+def main():
+    card_number = '4111-1111-4555-1142'
+    card_translation = str.maketrans({'-': '', ' ': ''})
+    translated_card_number = card_number.translate(card_translation)
+
+    print(translated_card_number)
+
+    verify_card_number(translated_card_number)
+
+main()
+```