Python 如何将列表分配给 Pandas 数据框的现有列？
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How to assign a list to existing column of Pandas Data Frame?
提问by erogol
I apply some functions and generate a new column values to a existing column of Pandas dataframe. However df['col1'] = new_listdoes not work to assign new list to the column. Is it the wrong way and what is the accurate way to apply such operation ?
我应用了一些函数并为 Pandas 数据框的现有列生成一个新列值。但是df['col1'] = new_list，无法将新列表分配给该列。这是错误的方法，应用这种操作的准确方法是什么？
回答by Roman Pekar
It should work if length of the list is equal to the number of rows in the DataFrame
如果列表的长度等于 DataFrame 中的行数，它应该可以工作
>>> df = pd.DataFrame({'A':[1,2,3], 'B':[4,5,6]})
>>> df['C'] = [10,20,30]
>>> df
A B C
0 1 4 10
1 2 5 20
2 3 6 30
If your list is shorter or longer than DataFrame, then you'll receive an error Length of values does not match length of index.
如果您的列表比 DataFrame 短或长，那么您将收到错误消息Length of values does not match length of index。
