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Python 201 - Interactively Learn Advanced Concepts in Python 3

takewhile(), tee() and zip_longest()

Explore the functions takewhile, tee, and zip_longest from Python's itertools module. Understand how takewhile filters elements based on a predicate, tee duplicates iterators from a single iterable, and zip_longest combines iterables of different lengths using a fill value. Gain the skills to manipulate iterators effectively in Python.

We'll cover the following...

takewhile(predicate, iterable)

The takewhile module is basically the opposite of the dropwhile iterator that we looked at earlier. takewhile will create an iterator that returns elements from the iterable only as long as our predicate or filter is True. Let’s try a simple example to see how it works:

Python 3.5
from itertools import takewhile
print (list(takewhile(lambda x: x<5, [1,4,6,4,1])))
#[1, 4]

Here we run takewhile using a lambda function and a list. The ...