How can I use itertools to flatten a nested list in Python?

How can I use itertools to flatten a nested list in Python?

You can use itertools.chain to flatten a nested list. Here's an example: flattened = list(itertools.chain.from_iterable(nested_list)).

Can you show me a complete example with a nested list?

Sure! Here's a complete example:

import itertools
nested_list = [[1, 2, 3], [4, 5], [6]]
flattened = list(itertools.chain.from_iterable(nested_list))
print(flattened)  # Output: [1, 2, 3, 4, 5, 6]

What if my nested list has more than two levels?

In that case, you can use a recursive function to flatten it. Would you like to see an example?

Yes, please!

Here's a recursive function to flatten a nested list:

def flatten(nested):
    for item in nested:
        if isinstance(item, list):
            yield from flatten(item)
        else:
            yield item

nested_list = [1, [2, [3, 4], 5], 6]
flattened = list(flatten(nested_list))
print(flattened)  # Output: [1, 2, 3, 4, 5, 6]