如何根据行值按整数列表对熊猫进行划分

Question

我有一个数据框架：

import pandas as pd
import numpy as np

df = pd.DataFrame({ 'CITY' : np.random.choice(['PHOENIX','ATLANTA','CHICAGO', 'MIAMI', 'DENVER'], 1000),
                    'DAY': np.random.choice(['Monday','Tuesday','Wednesday', 'Thursday', 'Friday', 'Saturday', 'Sunday'], 1000),
                    'LOCATION' : np.random.choice(['Location1','Location2','Location3', 'Location4', 'Location5'], 1000),
                    'COUNT': np.random.randint(1, 700, size=1000)})

print(df)

         CITY  COUNT        DAY   LOCATION
0      DENVER    521  Wednesday  Location4
1       MIAMI    123   Saturday  Location3
2     ATLANTA    122  Wednesday  Location3
3      DENVER    363   Saturday  Location1
4     PHOENIX    656   Saturday  Location4
5     PHOENIX    369   Saturday  Location3
6       MIAMI    455    Tuesday  Location5

如何将计数列除以基于位置的整数列表，如

• 如果location1将计数除以13
• 如果location2将计数除以85
• 如果location3将计数除以42
• 如果地点除以intx.

Answer 1

我不太熟悉.map()，所以我的方法是(这可能在计算上有点昂贵)：

df['COUNT'] = None locations = {location: to_divide_by, location2: to_divide_by2} # and so on for index, row in df.iterrows(): df['COUNT'][index] = row['COUNT'] / locations[row['LOCATION']]