I have the following DataFrame in pandas:

For the district column if the row value is nan, I want to assign it the same value it has in its city attribute. Example:

CodePudding user response：

You should be able to use fillna() and pass the other column name:

df['district'] = df['district'].fillna(df['city'])

If the value is not Null (which I suggest to have it Null for best practices) but an empty string, you can evaluate a condition, so that:

df['district'] = np.where(df['district'] == '',df['city'],df['district'])