Lambda with filter() in Python - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to filter out even numbers from the list.

Python

numbers = [1, 2, 3, 4, 5, 6]
even_numbers = list(filter(lambda x: x [1] 2 == 0, numbers))
print(even_numbers)

Drag options to blanks, or click blank then click option'

A**

B//

C%

D+

Attempts:

3 left

💡 Hint

Common Mistakes

Using integer division '//' instead of modulo '%'.

Using exponent '**' or addition '+' operators incorrectly.

The modulo operator % returns the remainder. Using x % 2 == 0 checks if a number is even.

2fill in blank

medium

Complete the code to filter words longer than 4 characters.

Python

words = ['apple', 'bat', 'carrot', 'dog']
long_words = list(filter(lambda word: len(word) [1] 4, words))
print(long_words)

Drag options to blanks, or click blank then click option'

A<

B>

C==

D<=

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<' instead of '>' which filters shorter words.

Using '==' which filters words exactly 4 characters long.

We want words longer than 4 characters, so we use len(word) > 4.

3fill in blank

hard

Fix the error in the lambda to filter numbers less than 10.

Python

nums = [5, 12, 7, 20, 3]
small_nums = list(filter(lambda n: n [1] 10, nums))
print(small_nums)

Drag options to blanks, or click blank then click option'

A<=

B>

C==

D<

Attempts:

3 left

💡 Hint

Common Mistakes

Using '>' which filters numbers greater than 10.

Using '<=' which includes 10, but we want strictly less.

To filter numbers less than 10, use n < 10.

4fill in blank

hard

Fill both blanks to filter words starting with letter 'a' and having length less than 5.

Python

words = ['apple', 'ant', 'bat', 'arc', 'dog']
filtered = list(filter(lambda w: w[1] 'a' and len(w) [2] 5, words))
print(filtered)

Drag options to blanks, or click blank then click option'

Astartswith(

B==

C<

D>

Attempts:

3 left

💡 Hint

Common Mistakes

Using '==' to compare the whole word instead of checking start.

Using '>' instead of '<' for length comparison.

Use w.startswith('a') to check the first letter and len(w) < 5 for length less than 5.

5fill in blank

hard

Fill both blanks to create a dictionary of words and their lengths, filtering words longer than 3 characters.

Python

words = ['sun', 'moon', 'star', 'sky']
result = {w:: len(w) [1] w in words if len(w) [2] 3}
print(result)

Drag options to blanks, or click blank then click option'

Bfor

C>

D:

Attempts:

3 left

💡 Hint

Common Mistakes

Missing colon ':' between key and value.

Using incorrect loop keyword.

Using '<' instead of '>' for filtering.

The dictionary comprehension syntax is {key: value for item in iterable if condition}. Here, w: len(w), for w in words, and len(w) > 3.