Python pandas.DataFrame调整列顺序及修改index名

时间:2023-03-09 03:09:57
Python pandas.DataFrame调整列顺序及修改index名

1. 从字典创建DataFrame

>>> import pandas
>>> dict_a = {'user_id':['webbang','webbang','webbang'],'book_id':['','',''],'rating':['','',''],'mark_date':['2017-03-07','2017-03-07','2017-03-07']}
>>> df = pandas.DataFrame(dict_a) # 从字典创建DataFrame
>>> df # 创建好的df列名默认按首字母顺序排序,和字典中的先后顺序并不一样,字典中是'user_id','book_id','rating','mark_date'
book_id mark_date rating user_id
0 3713327 2017-03-07 4 webbang
1 4074636 2017-03-07 4 webbang
2 26873486 2017-03-07 4 webbang

2. 调整列顺序

>>> df = df[['user_id','book_id','rating','mark_date']] # 调整列顺序为'user_id','book_id','rating','mark_date'
>>> df
user_id book_id rating mark_date
0 webbang 3713327 4 2017-03-07
1 webbang 4074636 4 2017-03-07
2 webbang 26873486 4 2017-03-07

3. 调整index为从1开始

>>> df.index = range(1,len(df) + 1) # 将index改成从1开始
>>> df
user_id book_id rating mark_date
1 webbang 3713327 4 2017-03-07
2 webbang 4074636 4 2017-03-07
3 webbang 26873486 4 2017-03-07

DataFrame操作汇总:http://www.cnblogs.com/huahuayu/p/8227494.html