Python问题——AttributeError: 'NoneType' object has no attribute 'append'

python提示AttributeError: 'NoneType' object has no attribute 'append'

 

 

Python问题——AttributeError: 'NoneType' object has no attribute 'append'

f=open("data.csv")
for line in f:
    line = line.strip("\n")
    ls = line.split(",")
    lt=[]
    for word in ls:
        word=word.strip()
        lt=lt.append(word)

    print(",".join(lt))
f.close()

After the problem is solved lt = lt.append (word) to lt.append (word).

The reason: append itself will be a modification, and returns None. The return value can not be re-assigned to a.