itertools.takewhile

Describing itertools.takewhile(condition, itr)

• The takewhile function is used to:

  • Cycle through each element of an iterable
  • Includes elements until any element fails the condition
  • Then, every element after that element is ignored
• This condition is based on the condition parameter
• This iterable is based on the itr parameter
• takewhile returns an iterator with elements until our condition fails
• The takewhile function is the inverse of dropwhile

Illustrating the takewhile Function

>>> from itertools import takewhile
>>> cond = lambda x: x<5
>>> nums = [1,4,6,4,1]

>>> itr = takewhile(cond, nums)
>>> for i in itr: print(i)
1
4

References

• Documentation of the Takewhile Function from Itertools