Python loc函数用法

DataFrame.loc[row_indexer, column_indexer]

import pandas as pd

data = {
    'Name': ['Alice', 'Bob', 'Charlie', 'David', 'Eve'],
    'Age': [25, 30, 35, 40, 45],
    'Gender': ['F', 'M', 'M', 'M', 'F'],
    'City': ['NY', 'LA', 'SF', 'CHI', 'BOS']
}

df = pd.DataFrame(data)
df.set_index('Name', inplace=True)

print(df)

         Age Gender City
Name                    
Alice     25      F   NY
Bob       30      M   LA
Charlie   35      M   SF
David     40      M  CHI
Eve       45      F  BOS

print(df.loc['Bob', 'Age'])

30

print(df.loc[['Bob', 'Charlie'], ['Age', 'City']])

         Age City
Name            
Bob       30   LA
Charlie   35   SF

print(df.loc[:, 'Age'])

Name
Alice      25
Bob        30
Charlie    35
David      40
Eve        45
Name: Age, dtype: int64

print(df.loc[df['Age'] > 35])

       Age Gender City
Name                  
David   40      M  CHI
Eve     45      F  BOS