Lambda Functions

What is the output of the following code?

items = ['apple', 'banana', 'cherry']
filtered = list(filter(lambda x: 'a' in x, items))
print(filtered)

A:

['apple', 'banana', 'cherry']

B:

['apple', 'banana']

C:

['apple']

D:

['banana']

Answer: B

The filter() function with the lambda filters items containing the letter 'a'.

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What is the result of the following code?

numbers = [1, 2, 3, 4, 5]
squared = list(map(lambda x: x ** 2 if x % 2 == 0 else x, numbers))
print(squared)

A:

[1, 4, 3, 16, 5]

B:

[1, 4, 9, 16, 25]

C:

[1, 2, 3, 4, 5]

D:

[1, 2, 9, 4, 25]

Answer: A

The lambda function squares even numbers and leaves odd numbers unchanged.

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What is the purpose of the functools.lru_cache() function when used with a lambda function?

A:

To create a memoized version of the lambda function.

B:

To create a filter object based on the lambda function's condition.

C:

To sort the elements of an iterable using the lambda function.

D:

To apply the lambda function to each element of an iterable.

Answer: A

functools.lru_cache() is used to create a memoized version of a function, including lambda functions, for efficient caching of results.

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When using the sorted() function with a lambda function to sort a list of dictionaries, how can you sort based on a specific key within each dictionary?

A:

sorted(dictionaries, lambda x: x['key'])

B:

sorted(dictionaries, key=lambda x: x['key'])

C:

sorted(dictionaries, sort_key=lambda x: x['key'])

D:

sorted(dictionaries, key='key')

Answer: B

The key parameter is used to specify the lambda function that extracts the specific key for sorting.

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In Python, how can a lambda function be used with the max() function to find the maximum length string in a list?

A:

max(strings, key=lambda x: x)

B:

max(strings, key=lambda x: len(x))

C:

max(strings, lambda x: len(x))

D:

max(strings, lambda x: x)

Answer: B

The key parameter is used to specify the lambda function that calculates the length of each string.

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Questions for: Lambda Functions