Python Quiz 2

Which of the following functions is not a built-in functional programming tool in Python?

• map()

• filter()

• reduce()

• sorted()

What is The map() function in Python

• Filters elements based on a condition

• Transforms each element using a function(apply on each element)

• Reduces a sequence to a single value

• Sorts a sequence

Which import is required to use reduce() in Python?

• import collections

• import itertools

• from functools import reduce

• from operator import reduce

What is the correct syntax of a lambda function?

Note:Without Storing in a variable

• lambda (x, y): x + y

• lambda x, y: x + y

• def lambda(x, y): return x + y

• def (x, y): return x + y

What will the following code output?

f = lambda x: x * 2

print(f(5))

• 5

• 10

• 25

• error

Which of the following statements about lambda is TRUE?

• lambda can contain multiple return statements.

• lambda can take multiple arguments but only one expression.

• lambda is faster than normal functions.

• lambda must always be named.

What does the code return?

add = lambda a, b=10: a + b

print(add(5))

• 5

• 10

• 15

• Error

Which of these is equivalent to the code below?

lambda x: x**2

• def square(x):

  return x**2

• def square(x):

  print(x**2)

• def square():

  return x**2

• Both a & b

Answer explanation

Option (a):

def square(x):

return x**2

This is equivalent, because it takes x and returns x² — exactly what the lambda does.

Option (b):

def square(x):

print(x**2)

This is not equivalent because:

• print() just displays the value, it does not return it.

• If you do result = square(5), in (a) you’ll get 25, but in (b) you’ll get None (because print() doesn’t return).

What will be the output?

nums = [1, 2, 3, 4]

print(list(map(lambda x: x+1, nums)))

• [1, 2, 3, 4]

• [2, 3, 4, 5]

• [0, 1, 2, 3]

• Error

Which is NOT true about lambda functions?

• They can be used inside map(), filter(), and reduce().

• They are anonymous functions.

• They can have multiple expressions.

• They can be assigned to variables.