Combining Iterables with FillValue

This function combines multiple iterable objects into an iterator. If an iterable object is shorter than the others, it fills the remaining positions with fillvalue

Technology Stack : itertools, collections

Code Type : Function

Code Difficulty : Intermediate

                
                    
def zip_longest(*iterables, fillvalue=None):
    # 这个函数将多个可迭代对象组合成一个迭代器，其中较短的迭代器用fillvalue填充
    from itertools import zip_longest
    from collections import deque

    def fill_values(fill_values, it):
        for item in it:
            fill_values.append(item)

    fill_values = deque()
    for iterable in iterables:
        fill_values.append(fillvalue)
        fill_values.extend(iterable)

    return zip_longest(fill_values, *iterables)