Pandas SettingWithCopyWarning：试图在 DataFrame 切片的副本上设置值
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Pandas SettingWithCopyWarning: A value is trying to be set on a copy of a slice from a DataFrame
提问by Dance Party
I keep getting the warning in the subject in the following situations:
在以下情况下，我不断收到该主题的警告：
df.rename(columns={'one':'one_a'}, inplace=True)
df.drop(['one', 'two', 'three'], axis=1, inplace=True)
df.rename(columns={'one':'one_a'}, inplace=True)
df.drop(['one', 'two', 'three'], axis=1, inplace=True)
How do I fix?
我该如何解决？
回答by maxymoo
Easiest fix (and probably good programming practice) would be to not do inplace operations, e.g.
最简单的修复（也可能是良好的编程实践）是不进行就地操作，例如
df2 = df.rename(columns={'one':'one_a'})
回答by tupan
I had a similar problem and to fix I did the following:
我有一个类似的问题，为了解决我做了以下事情：
new_df = df.copy()
new_df.rename(columns={'one':'one_a'}, inplace=True)
new_df.drop(['one', 'two', 'three'], axis=1, inplace=True)
Or you can do
或者你可以做
df.is_copy = False
You were probably using a copy of your original DF (ex: you were manipulating your DF before that) and that's why you were receiving the warning. More on copy:
您可能正在使用原始 DF 的副本（例如：您在此之前操作了 DF），这就是您收到警告的原因。更多关于副本：
