How to append a list to a list created by a function in Python

Question

Okay, I have a list that looks like this

OldList = [1000, 2000, 3000, 4000, 5000]

And I want to run all members of that list through a function called ListMultiply, like so

NewList = ListMultiply("/listfile/" + oldList]

How do I do this without concatenating string/list? Thanks.

Answer 1

NewList = [ListMultiply("/listfile/"+str(e)) for e in OldList]

上面的代码通过将字符串"/listfile/"到每个元素的字符串表示形式并将结果传递给ListMultiply()来创建一个新列表。

Answer 2

You should concatenate the string/list somewhere("".join or str.format would be better anyway), but I think you look something like:

>>> OldList = [1000, 2000, 3000, 4000, 5000]
>>> def f(x):
...     return x*2
... 
>>> OldList = [1000, 2000, 3000, 4000, 5000]
>>> NewList = [f("listfile/" + str(i)) for i in OldList]
>>> NewList
['listfile/1000listfile/1000', 'listfile/2000listfile/2000', 'listfile/3000listfile/3000', 'listfile/4000listfile/4000', 'listfile/5000listfile/5000']