List creation and representation in Python - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of list creation with mixed types

What is the output of this Python code?

Python

my_list = [1, '2', 3.0, True]
print(my_list)

A [1, '2', 3.0, True]

B [1, 2, 3.0, True]

C [1, '2', 3, True]

D [1, '2', 3.0, 1]

💡 Hint

Remember that strings and numbers are different types and are shown with quotes or without.

The list contains an integer 1, a string '2', a float 3.0, and a boolean True. The print shows them exactly as stored.

❓ Predict Output

intermediate

Length of a nested list

What is the value of len(my_list) after running this code?

Python

my_list = [1, [2, 3], 4]
print(len(my_list))

A 4

B 3

C 5

D TypeError

💡 Hint

len() counts the top-level items in the list, not inside nested lists.

The list has three items: 1, [2, 3], and 4. The nested list counts as one item.

❓ Predict Output

advanced

Output of list multiplication with nested lists

What is the output of this code?

Python

lst = [[0]] * 3
lst[0][0] = 5
print(lst)

A [[5], [5], [5]]

B [[0], [0], [0]]

C [[5], [0], [0]]

D TypeError

💡 Hint

Multiplying a list with nested lists copies references, not independent copies.

All three elements point to the same inner list. Changing one changes all.

❓ Predict Output

advanced

Output of list comprehension with condition

What is the output of this code?

Python

result = [x**2 for x in range(5) if x % 2 == 0]
print(result)

A SyntaxError

B [1, 9, 25]

C [0, 4, 16]

D [0, 1, 4, 9, 16]

💡 Hint

The condition filters only even numbers before squaring.

Only 0, 2, and 4 are even in range(5). Their squares are 0, 4, and 16.

🧠 Conceptual

expert

Understanding list identity after slicing

Consider this code. What is the output of the print statement?

Python

a = [1, 2, 3, 4]
b = a[:]
b[0] = 100
print(a[0])

A 100

B TypeError

C IndexError

D 1

💡 Hint

Slicing creates a new list copy, so changes to b do not affect a.

b is a copy of a. Changing b[0] does not change a[0]. So a[0] remains 1.