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我有一個csv文件,我作爲一個數據幀導入。這個數據幀經過多個過濾步驟。數據也根據條件在列之間移動。從現有創建新的數據幀 - SettingWithCopyWarning
import numpy as np
import pandas as pd
df = pd.read_csv('my_csv_file.csv', names=headers)
df2 = df.drop_duplicates(['Column_X'])
series1 = df2.loc[df2['Column_Y'] == 'Category1', 'Column_X']
df2.loc[df2['Column_Y'] == 'Category1', 'Column_Z'] = series1
...
將最後一行輸入命令提示符後,我得到SettingWithCopyWarning。
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.
請注意,我在我的代碼中使用了.loc。
執行以下操作,不會引發錯誤:
df.loc[df['Column_Y'] == 'Category1', 'Column_Z'] = series1
這讓我覺得這個問題是在使用DF2作爲一個新的數據幀。