CODEWITHSUNDEEP
pythonlambdalist-comprehension
wow yoo
wow yoo

Reputation: 895

What impact does the lambda section have in this list comprehension?

According to the syntax specification of comprehension ,[x for x in (1,2,3) if lambda x :x-2] is valid. However,[x for x in (1,2,3)]has the same result .What impact does the lambda section have in this list comprehension?

Upvotes: 0

Views: 40

Answers (1)

chepner
chepner

Reputation: 532478

It has no impact. The lambda expression defines a function object, and the if guard in a list comprehension expects a Boolean value. The "truthiness" of a function object is always True, so the list comprehension is exactly the same as

[x for x in (1,2,3) if True]

If you actually called the resulting function, such as with

[x for x in (1,2,3) if (lambda y :y-2)(x)]

then you would have an actual filter that effectively checks if a value is not equal to 2. (y - 2 will be non-zero, and thus True, for any value of y other than 2.)

Upvotes: 6

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