Built-in Functions and Lambdas Flashcards

What does `list(map(lambda x: x ** 2, [1, 2, 3, 4]))` return?

Answer: [1, 4, 9, 16]

map applies the lambda squaring function to each element, producing [1, 4, 9, 16].

Which built-in function returns the largest item in an iterable?

Answer: max()

max() returns the largest item from an iterable or the largest of two or more arguments.

What is the output of `list(filter(lambda x: x % 2 == 0, range(10)))`?

Answer: [0, 2, 4, 6, 8]

filter keeps elements where the lambda returns True, selecting even numbers 0 through 8.

What does `abs(-7.5)` return?

Answer: 7.5

abs() returns the absolute value of a number, converting -7.5 to 7.5.

What is the result of `sorted([3,1,4,1,5], reverse=True)`?

Answer: [5, 4, 3, 1, 1]

sorted() with reverse=True returns a new list sorted in descending order.

Which of the following correctly uses a lambda with `sorted()` to sort by the second element of each tuple?

Answer: sorted(lst, key=lambda x: x[1])

The key parameter accepts a callable; lambda x: x[1] extracts the second element for comparison.

What does `any([False, False, True, False])` return?

Answer: True

any() returns True if at least one element in the iterable is truthy.