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Python Pandas DataFrame.idxmax() 函数返回行或列中最大值的索引。

pandas.DataFrame.idxmax() 的语法

DataFrame.idxmax(axis=0, skipna=True)

参数

返回值

它返回一个 Series，代表沿指定轴的最大值的索引。

示例代码: DataFrame.idxmax() 按行查找最大数值索引

import pandas as pd

dataframe=pd.DataFrame({'Attendance': {0: 60, 1: 100, 2: 80,3: 78,4: 95},
                        'Obtained Marks': {0: 90, 1: 75, 2: 82, 3: 64, 4: 45}})
print("The Original Data frame is: \n")
print(dataframe)

series = dataframe.idxmax()
print("The Indexes are: \n")
print(series)

输出：

The Original Data frame is: 

   Attendance  Obtained Marks
0          60              90
1         100              75
2          80              82
3          78              64
4          95              45
The Indexes are: 

Attendance        1
Obtained Marks    0
dtype: int64

函数返回最大 Attendance 和 Obtained Marks 的索引。

示例代码：DataFrame.idxmax() 按列查找最大值索引

import pandas as pd

dataframe=pd.DataFrame({'Attendance': {0: 60, 1: 100, 2: 80,3: 78,4: 95},
                        'Obtained Marks': {0: 90, 1: 75, 2: 82, 3: 64, 4: 45}})
print("The Original Data frame is: \n")
print(dataframe)

series = dataframe.idxmax(axis= 1)
print("The Indexes are: \n")
print(series)

输出：

The Original Data frame is: 

   Attendance  Obtained Marks
0          60              90
1         100              75
2          80              82
3          78              64
4          95              45
The Indexes are: 

0    Obtained Marks
1        Attendance
2    Obtained Marks
3        Attendance
4        Attendance
dtype: object

该函数按列返回索引。