CODEWITHSUNDEEP
pythondictionary
Hassan Ibrahim
Hassan Ibrahim

Reputation: 3

Passing one value along with a list to a map in python

I tried to map the function math.pow with the power of 2 to a list, but the problem is that I should pass an iterable not just a single value. So, I fixed it this way, by making a list of 2s with the same length as my list:

import math
lis = [1,2,3,4]
squred_lis = list(map(math.pow, lis, [2,2,2,2]))
print (squred_lis)

So, is there a way I can just pass a single value and have it passed every iteration as the second argument?

Upvotes: 0

Views: 464

Answers (2)

sj95126
sj95126

Reputation: 6908

I think what you're looking for is itertools.repeat(). It will repeat the value infinitely, and map() will iterate as many of them as necessary to match the length of lis.

import math
import itertools

lis = [1,2,3,4]
squared_lis = list(map(math.pow, lis, itertools.repeat(2)))
print(squared_lis)

which produces:

[1.0, 4.0, 9.0, 16.0]

Upvotes: 1

WillSmith
WillSmith

Reputation: 104

I think this is what you want

squred_lis = list(map(math.pow, lis, [2 for _ in range(len(a))]))

but.. how about this?

squared_list = list(map(lambda x: x ** 2, a))

Upvotes: 0

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