我试图找出如何在pandas元素中拆分字符串,然后重新组合拆分字符串的一部分。我有以下代码:
import pandas as pd
df = pd.DataFrame({'code': ['PC001-S002_D_CFI4-1_NN','PC001-S002_D_CFI4-1_NN','PC001-S002_D_CFI4-1_NN',
'PC001-S002_D_CFI4-1_ER','PC001-S002_D_CFI4-1_ER','PC001-S002_D_CFI4-1_ER']})
df['domain'] = df['code'].str.split("_")
此代码适用于在下划线上拆分字符串。现在,我想在列中获取生成的拆分列表,并重新组合前三个元素,以便:
PC001-S001_D_CFI4-1_NN ==>的 PC001-S001_D_CFI4-1
如果我只是使用:
申请字符串,我可以这样做a = 'PC001-S002_D_CFI4-1_NN'
b = a.split("_")[0:3]
c = "_".join(b)
然而,我试图将此应用于熊猫而没有太大成功。
任何建议都会得到很好的接受。
答案 0 :(得分:4)
您可以使用Series.str.rsplit(...):
In [11]: df['domain'] = df['code'].str.rsplit('_',1).str[0]
In [12]: df
Out[12]:
code domain
0 PC001-S002_D_CFI4-1_NN PC001-S002_D_CFI4-1
1 PC001-S002_D_CFI4-1_NN PC001-S002_D_CFI4-1
2 PC001-S002_D_CFI4-1_NN PC001-S002_D_CFI4-1
3 PC001-S002_D_CFI4-1_ER PC001-S002_D_CFI4-1
4 PC001-S002_D_CFI4-1_ER PC001-S002_D_CFI4-1
5 PC001-S002_D_CFI4-1_ER PC001-S002_D_CFI4-1
或者只删除最后一部分:
In [7]: df['domain'] = df['code'].str.replace(r'\_\w+?$','')
In [8]: df
Out[8]:
code domain
0 PC001-S002_D_CFI4-1_NN PC001-S002_D_CFI4-1
1 PC001-S002_D_CFI4-1_NN PC001-S002_D_CFI4-1
2 PC001-S002_D_CFI4-1_NN PC001-S002_D_CFI4-1
3 PC001-S002_D_CFI4-1_ER PC001-S002_D_CFI4-1
4 PC001-S002_D_CFI4-1_ER PC001-S002_D_CFI4-1
5 PC001-S002_D_CFI4-1_ER PC001-S002_D_CFI4-1
答案 1 :(得分:3)
使用str[:3]
选择前3 list
,然后join
:
df['domain'] = df['code'].str.split("_").str[:3].str.join('_')
print (df)
code domain
0 PC001-S002_D_CFI4-1_NN PC001-S002_D_CFI4-1
1 PC001-S002_D_CFI4-1_NN PC001-S002_D_CFI4-1
2 PC001-S002_D_CFI4-1_NN PC001-S002_D_CFI4-1
3 PC001-S002_D_CFI4-1_ER PC001-S002_D_CFI4-1
4 PC001-S002_D_CFI4-1_ER PC001-S002_D_CFI4-1
5 PC001-S002_D_CFI4-1_ER PC001-S002_D_CFI4-1