Pandas Dataframe 行选择组合条件索引和列值
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Pandas Dataframe row selection combined condition index- and column values
提问by Egirus Ornila
I want to select rows from a dataframe based on values in the index combined with values in a specific column:
我想根据索引中的值和特定列中的值从数据框中选择行：
df = pd.DataFrame([[0, 2, 3], [0, 4, 1], [0, 20, 30], [40, 20, 30]],
index=[4, 5, 6, 7], columns=['A', 'B', 'C'])
A B C
4 0 2 3
5 0 4 1
6 0 20 30
7 40 20 30
with
和
df.loc[df['A'] == 0, 'C'] = 99
i can select all rows with column A = 0 and replace the value in column C with 99, but how can i select all rows with column A = 0 and the index < 6 (i want to combine selection on the index with selection on the column)?
我可以选择 A 列 = 0 的所有行并将 C 列中的值替换为 99，但是如何选择 A 列 = 0 且索引 < 6 的所有行（我想将索引上的选择与柱子）？
采纳答案by sacuL
You can use multiple conditions in your locstatement:
您可以在loc语句中使用多个条件：
df.loc[(df.index < 6) & (df.A == 0), 'C'] = 99
