List Practice Problems

The best way to master lists is by solving problems. This lab contains a series of hands-on exercises, from basic to advanced, to solidify your understanding. Each problem includes an interactive runner so you can test your solution instantly.

Beginner Exercises

These problems focus on fundamental list creation, indexing, and basic methods.

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Create a list containing the first five positive integers. Then, print the element at index 2.

Expected Output:

The list is: [1, 2, 3, 4, 5]
The element at index 2 is: 3

Output:

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You have a list of groceries. Add 'bread' to the end of the list and then print the modified list.

Expected Output:

['milk', 'eggs', 'cheese', 'bread']

Output:

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Given a list of numbers, create a new list containing only the numbers greater than 10.

Expected Output:

[12, 15, 20]

Output:

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Check if the name 'Alice' is present in a list of attendees.

Expected Output:

Is Alice attending? True

Output:

Intermediate Exercises

These problems involve slicing, comprehensions with conditions, and more complex methods.

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Flatten a nested list [[1, 2], [3, 4], [5]] into a single list [1, 2, 3, 4, 5] using a list comprehension.

Expected Output:

[1, 2, 3, 4, 5]

Output:

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Remove all duplicate values from the list ['a', 'b', 'a', 'c', 'b'] while preserving the original order of the first occurrence.

Expected Output:

['a', 'b', 'c']

Output:

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Split a list of numbers from 1 to 12 into a list of sublists (chunks) of size 4.

Expected Output:

[[1, 2, 3, 4], [5, 6, 7, 8], [9, 10, 11, 12]]

Output:

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Given a list of scores, find the top 3 scores without modifying the original list.

Expected Output:

Top 3 scores: [99, 91, 87]
Original scores remain unchanged: [55, 87, 91, 60, 73, 99, 81]

Output:

Advanced Exercises

These problems require combining multiple concepts, using helper modules, or understanding more complex patterns.

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Transpose a 3x2 matrix so that rows become columns. For [[1, 2], [3, 4], [5, 6]], the result should be [[1, 3, 5], [2, 4, 6]].

Expected Output:

[[1, 3, 5], [2, 4, 6]]

Output:

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Find the most common element in a list of strings.

Expected Output:

The most common word is: 'apple'

Output:

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Create a frequency map (dictionary) of characters for the string 'programming'.

Expected Output:

{'a': 1, 'g': 2, 'i': 1, 'm': 2, 'n': 1, 'o': 1, 'p': 1, 'r': 2}

Output:

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Rotate a list by a given number of steps to the right. For a list [1, 2, 3, 4, 5] and k=2, the result should be [4, 5, 1, 2, 3].

Expected Output:

Original: [1, 2, 3, 4, 5, 6, 7]
Rotated by 3: [5, 6, 7, 1, 2, 3, 4]