Python - 将 Pandas DataFrame 与外部连接合并
要合并PandasDataFrame，请使用该merge()函数。通过在merge()函数的“如何”参数下设置，在两个数据帧上实现外连接，即-
how = “outer”
首先，让我们使用别名导入pandas库-
import pandas as pd
让我们创建DataFrame1-
dataFrame1 = pd.DataFrame(
{
"Car": ['BMW', 'Lexus', 'Audi', 'Mustang', 'Bentley', 'Jaguar'],
"Units": [100, 150, 110, 80, 110, 90]
}
)现在让我们创建DataFrame2-
dataFrame2 = pd.DataFrame(
{
"Car": ['BMW', 'Lexus', 'Tesla', 'Mustang', 'Mercedes', 'Jaguar'],
"Reg_Price": [7000, 1500, 5000, 8000, 9000, 6000]
}
)将DataFrames与公共列Car和“how”参数中的“outer”合并以实现OuterJoin-
mergedRes = pd.merge(dataFrame1, dataFrame2, on ='Car', how ="outer")
示例
以下是代码-
import pandas as pd
#CreateDataFrame1
dataFrame1 = pd.DataFrame(
{
"Car": ['BMW', 'Lexus', 'Audi', 'Mustang', 'Bentley', 'Jaguar'],
"Units": [100, 150, 110, 80, 110, 90]
}
)
print"DataFrame1 ...\n",dataFrame1
#CreateDataFrame2
dataFrame2 = pd.DataFrame(
{
"Car": ['BMW', 'Lexus', 'Tesla', 'Mustang', 'Mercedes', 'Jaguar'],
"Reg_Price": [7000, 1500, 5000, 8000, 9000, 6000]
}
)
print"\nDataFrame2 ...\n",dataFrame2
# merge DataFrames with common column Car and "outer" in "how" parameter implements Outer Join
mergedRes = pd.merge(dataFrame1, dataFrame2, on ='Car', how ="outer")
print"\nMerged dataframe with outer join...\n", mergedRes输出结果这将产生以下输出-
DataFrame1 ...
Car Units
0 BMW 100
1 Lexus 150
2 Audi 110
3 Mustang 80
4 Bentley 110
5 Jaguar 90
DataFrame2 ...
Car Reg_Price
0 BMW 7000
1 Lexus 1500
2 Tesla 5000
3 Mustang 8000
4 Mercedes 9000
5 Jaguar 6000
Merged dataframe with outer join...
Car Units Reg_Price
0 BMW 100.0 7000.0
1 Lexus 150.0 1500.0
2 Audi 110.0 NaN
3 Mustang 80.0 8000.0
4 Bentley 110.0 NaN
5 Jaguar 90.0 6000.0
6 Tesla NaN 5000.0
7 Mercedes NaN 9000.0