Python 试图获取不等于列表的元素时，SettingWithCopyWarning

我试图删除数据帧中与列表中元素不相等的所有内容，但收到以下警告：

C:/Users/jalco/PycharmProjects/project/main.py:119: SettingWithCopyWarning: 
A value is trying to be set on a copy of a slice from a DataFrame.
Try using .loc[row_indexer,col_indexer] = value instead

See the caveats in the documentation: https://pandas.pydata.org/pandas-docs/stable/user_guide/indexing.html#returning-a-view-versus-a-copy
  df[sample'] = ''
C:/Users/jalco/PycharmProjects/project/main.py:120: SettingWithCopyWarning: 
A value is trying to be set on a copy of a slice from a DataFrame.
Try using .loc[row_indexer,col_indexer] = value instead

See the caveats in the documentation: https://pandas.pydata.org/pandas-docs/stable/user_guide/indexing.html#returning-a-view-versus-a-copy
  df['sample'] = np.where((df['num'] > 0) &

以下是导致警告的代码：

if not config_dict['admin']:
    df = df[~df['transtype'].isin(transtype['admin'])]

if 'sample' in config_dict['links']:
    df['sample'] = ''
    df['sample'] = np.where((df['num'] > 0) &
                                    (df['transtype'] == df['coll']),
                                    df['num'], df['sample'])

我的问题是“是否有更好的方法删除我不需要的行，或者我只是手动关闭警告？”

谢谢

我会在实际创建

df

时添加

.copy（）

，因为这似乎是问题的根源，然后您可以尝试为列分配

.loc[]

。您还可以通过简单地使用以下命令来保存一行代码：

df.loc[:,'sample']  = np.where((df['num'] > 0) &
                                (df['transtype'] == df['coll']),
                                df['num'], ''])

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你能给我们展示一个最小的数据样本，这样我们就可以重现警告了吗？