List comprehension vs map

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长情又很酷
长情又很酷 2020-11-21 04:39

Is there a reason to prefer using map() over list comprehension or vice versa? Is either of them generally more efficient or considered generally more pythonic

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  •  独厮守ぢ
    2020-11-21 04:55

    I consider that the most Pythonic way is to use a list comprehension instead of map and filter. The reason is that list comprehensions are clearer than map and filter.

    In [1]: odd_cubes = [x ** 3 for x in range(10) if x % 2 == 1] # using a list comprehension
    
    In [2]: odd_cubes_alt = list(map(lambda x: x ** 3, filter(lambda x: x % 2 == 1, range(10)))) # using map and filter
    
    In [3]: odd_cubes == odd_cubes_alt
    Out[3]: True
    

    As you an see, a comprehension does not require extra lambda expressions as map needs. Furthermore, a comprehension also allows filtering easily, while map requires filter to allow filtering.

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