用多個條件過濾 Pandas DataFrame
Suraj Joshi
2023年1月30日
本教程解釋瞭如何基於多個條件從 DataFrame 中過濾元素。
我們將在本文中使用下面的 DataFrame。
import pandas as pd
stocks_df = pd.DataFrame(
{
"Stock": ["Tesla", "Moderna Inc", "Facebook", "Boeing"],
"Price": [835, 112, 267, 209],
"Sector": ["Technology", "Health Technology", "Technology", "Aircraft"],
}
)
print(stocks_df)
輸出：
Stock Price Sector
0 Tesla 835 Technology
1 Moderna Inc 112 Health Technology
2 Facebook 267 Technology
3 Boeing 209 Aircraft
根據多個條件使用索引過濾 DataFrame 的元素
import pandas as pd
stocks_df = pd.DataFrame(
{
"Stock": ["Tesla", "Moderna Inc", "Facebook", "Boeing"],
"Price": [835, 112, 267, 209],
"Sector": ["Technology", "Health Technology", "Technology", "Aircraft"],
}
)
print("Stocks DataFrame:")
print(stocks_df, "\n")
reqd_stocks = stocks_df[(stocks_df.Sector == "Technology") & (stocks_df.Price < 500)]
print("The stocks of technology sector with price less than 500 are:")
print(reqd_stocks)
輸出：
Stocks DataFrame:
Stock Price Sector
0 Tesla 835 Technology
1 Moderna Inc 112 Health Technology
2 Facebook 267 Technology
3 Boeing 209 Aircraft
The stocks of technology sector with price less than 500 are:
Stock Price Sector
2 Facebook 267 Technology
它過濾了 stocks_df 中的所有元素，其中 Sector 列的值是 Technology，Price 列的值小於 500。
我們在 [] 內指定條件，用&或|運算子連線條件，根據多個條件對數值進行索引。&運算子代表邏輯和，意思是這兩個條件必須為真才能選擇一個元素。|運算子代表邏輯或，意思是如果滿足任何條件就可以選擇一個元素。
使用 query() 方法基於多個條件過濾 DataFrame 的元素
我們將由&或|運算子連線的多個條件作為引數傳遞給 query() 方法。
import pandas as pd
stocks_df = pd.DataFrame(
{
"Stock": ["Tesla", "Moderna Inc", "Facebook", "Boeing"],
"Price": [835, 112, 267, 209],
"Sector": ["Technology", "Health Technology", "Technology", "Aircraft"],
}
)
print("Stocks DataFrame:")
print(stocks_df, "\n")
reqd_stocks = stocks_df.query("Sector == 'Technology' & Price <500")
print("The stocks of technology sector with price less than 500 are:")
print(reqd_stocks)
輸出：
Stocks DataFrame:
Stock Price Sector
0 Tesla 835 Technology
1 Moderna Inc 112 Health Technology
2 Facebook 267 Technology
3 Boeing 209 Aircraft
The stocks of technology sector with price less than 500 are:
Stock Price Sector
2 Facebook 267 Technology
作者： Suraj Joshi
Suraj Joshi is a backend software engineer at Matrice.ai.
LinkedIn