Difference between takewhile() and map() function

Question

num = [0,1,3,6,10,15,21,28]
print(list(takewhile(lambda x : x<=6 , nums)))
print(list(map(lambda x : x<=6 , nums)))

output is-----

[0, 1, 3, 6]
[True, True, True, True, False, False, False, False] and why not [0,1,3,6]

why the output of map() function displays in True False...

But in

def add_five(x):
return x+5

nums = [11,22,33,44,55]
result = list(map(add_five,nums))
print(result)

output ---
[16, 27, 38, 49, 60]

I am not getting how map() works??

Answer 1

takewhile() stops as soon as the first non-fitting element is found. That's 10 in your list 'num'. Even if there are more elements after 10 that meet the requirement of x <= 6, takewhile won't find them. map() iterates over the whole list and finds every element that is <= 6.

In general, map() is used to apply a function to a set or list of values. In your first example, the lambda function will return True for every number <= 6 and False for every other number. map() applies this lambda function on the list 'num'. So the result is a list of booleans.

Answer 2

never seen the "takewhile" function o_O

anyway, you can use "filter" instead of "map" and it will give you [0, 1, 3, 6] (and any other value which meets the criteria unlike "takewhile" which stops once a non fitting element is encountered)

Answer 3

Burey takewhile is part of itertools 🤓