英文:
How to add together two columns in pandas without receiving SettingWithCopyWarning
问题
尝试使用pandas将一列添加到另一列：
merged_df.loc[:, 'airline_name'] = merged_df.loc[:, 'airline_name'] + merged_df['airline_icao_unique_code']
但每次尝试时都会收到警告：
> SettingWithCopyWarning:
试图在DataFrame的切片副本上设置值。
请尝试使用.loc[row_indexer, col_indexer] = value来替代
详细信息请参阅文档：https://pandas.pydata.org/pandas-docs/stable/user_guide/indexing.html#returning-a-view-versus-a-copy
self.obj[selected_item_labels] = value
进程以退出代码0完成
有没有办法在不触发此警告的情况下执行此操作？我已尝试更改语法并创建临时变量，但似乎无法使其正常工作。我还尝试使用.copy()函数，但仍然无法成功。
英文:
Trying to add add one column to another using pandas with:
merged_df.loc[:, 'airline_name'] = merged_df.loc[:, 'airline_name'] + merged_df['airline_icao_unique_code']
but every time I try I receive the warning :
> 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
self.obj[selected_item_labels] = value
Process finished with exit code 0
Is there any way to do this without triggering this warning? I have tried altering the syntax and creating temporary variables but I cant seem to get it to work. I have also tried using the .copy() function but still no dice.
答案1
得分: 1
这可能是因为merged_df是另一个DataFrame的子集。修复这个问题的最简单方法是在执行此操作之前使用.copy()：
merged_df = merged_df.copy()
merged_df['airline_name'] = merged_df['airline_name'] + merged_df['airline_icao_unique_code']
英文:
This is likely due to merged_df being a subset of another DataFrame. The easiest way to fix this is to use .copy() before performing this operation:
merged_df = merged_df.copy()
merged_df['airline_name'] = merged_df['airline_name'] + merged_df['airline_icao_unique_code']
答案2
得分: 0
merged_df['airline_name'] = merged_df['airline_name'] + merged_df['airline_icao_unique_code']
英文:
merged_df['airline_name'] = merged_df['airline_name'] + merged_df['airline_icao_unique_code']
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