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python中map的结果为什么一定要list处理?

def foo(income):
    return("income"+str(income))

r=map(foo,["A","B","C"])
print(r)
r1=list(map(foo,["A","B","C"]))
print(r1)

image.png
为什么map的结果一定要list处理?这两个感觉不是一路货啊


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因为python3的map结果是一个迭代器对象,python2的map结果才是一个数组。

迭代器就是可以用来循环迭代取值,list可以一次性拿到迭代器所有元素并放到数组里,这是强制类型转换的过程,把迭代器转为数组。


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