获取pandas数据帧中的特定值

Question

我有一个名为df的数据帧

       season   seed    team
1609    2010    W01     1246
1610    2010    W02     1452
1611    2010    W03     1307
1612    2010    W04     1458
1613    2010    W05     1396

我需要以下格式的新数据帧：

team  frequency
1246    01 
1452    02 
1307    03
1458    04
1396    05

frequency值来自数据帧df中名为seed的列

W01 -> 01
W02 -> 02
W03 -> 03

我该如何在熊猫身上做到这一点？你知道吗

Answer 1

下面的解决方案使用lambda函数应用regex来删除非数字字符。你知道吗

http://pythex.org/?regex=%5CD&test_string=L16a&ignorecase=0&multiline=0&dotall=0&verbose=0

import pandas as pd
import re

index=[1609,1610,1611,1612,1613,1700]
data = {'season':[2010,2010,2010,2010,2010,2010],
        'seed':['W01','W02','W03','W04','W05','L16a'],
        'team':[1246,1452,1307,1458,1396,0000]}

df = pd.DataFrame(data,index=index)

df['frequency'] = df['seed'].apply(lambda x: int(re.sub('\D', '', x)))
df2 = df[['team','frequency']].set_index('team')

Answer 2

# Setup your DataFrame
df = pd.DataFrame({'season': [2010]*5, 'seed': ['W0' + str(i) for i in range(1,6)], 'team': [1246, 1452, 1307, 1458, 1396]}, index=range(1609, 1614))
s = pd.Series(df['seed'].str[1:].values, index=df['team'], name='frequency')
print(s)

收益率

team
1246    01
1452    02
1307    03
1458    04
1396    05
Name: frequency, dtype: object