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Lists & loops

Iterate, transform, and combine sequences with readable loop patterns.

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Lists & loops easy

How to Pad a List to Length n in Python with a Fill Value

Create a reusable function that pads a Python list to a specified length n by appending a fill value, or truncates it when the list is already longer than n.

lists padding slicing
Python 
def pad_list(lst, n, fill_value=None):
    """
    Pad a list to length n using fill_value for missing elements.
    If the list is longer than n, it is truncated to length n.
    """
    if n <= len(lst):
        return lst[:n]
    return lst + [fill_value] * (n - len(lst))


if __name__ == "__main__":
    # Examples…
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