Lambda Functions

What does the following lambda function accomplish?

lambda x: x.split()[0] if isinstance(x, str) else None

A:

Extracts the first word of a string and returns None for non-string values.

B:

Converts a string to uppercase and returns None for non-string values.

C:

Joins all words in a string and returns None for non-string values.

D:

Returns the length of a string and None for non-string values.

Answer: A

The lambda function extracts the first word of a string and returns None for non-string values.

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When using the sorted() function with a lambda function to sort a list of tuples, how can you sort based on the second element of each tuple?

A:

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

B:

sorted(tuples, sort_key=lambda x: x[1])

C:

sorted(tuples, key=tuple[1])

D:

sorted(tuples, sort_key=tuple[1])

Answer: A

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

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What does the following lambda function do?

lambda x, y: x + y

A:

Concatenates two strings.

B:

Multiplies two numbers.

C:

Adds two numbers.

D:

Raises one number to the power of another.

Answer: C

The lambda function adds two numbers.

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What is the purpose of the reduce() function when used with a lambda function?

A:

To filter elements from an iterable based on the lambda function's condition.

B:

To create a sorted list based on the lambda function's values.

C:

To apply the lambda function cumulatively to the items of an iterable.

D:

To combine two iterables into a single iterable of tuples.

Answer: C

The reduce() function is used to apply the lambda function cumulatively to the items of an iterable.

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How can a lambda function be used with the min() function to find the minimum length string in a list of strings?

A:

min(strings, key=len)

B:

min(strings, lambda x: x)

C:

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

D:

min(strings, key=lambda x: x)

Answer: A

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