Python附加错误 [英] Python appending error

问题描述

x = []
with open(filechoice) as fileobj:
    for word in fileobj:  
       for ch in word:

           f = ord(ch)
           x = x.append(ord(ch))

但它返回此错误：

"AttributeError: 'NoneType' object has no attribute 'append'"

如何解决此错误？

推荐答案

list.append（）方法返回 None ，并且您已替换存储在 x 中且具有返回值的列表：

The list.append() method returns None, and you replaced the list stored in x with that return value:

x = x.append(ord(ch))

不要分配回 x 在这里； list.append（）修改列表 ：

Don't assign back to x here; list.append() alters the list in place:

with open(filechoice) as fileobj:
    for word in fileobj:  
       for ch in word:
           x.append(ord(ch))

您可以使用列表理解来构建列表：

You can use a list comprehension to build the list instead:

with open(filechoice) as fileobj:
    x = [ord(ch) for word in fileobj for ch in word]

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