Python pandas.DataFrame调整列顺序及修改index名的方法

> import pandas
> dict_a = {'user_id':['webbang','webbang','webbang'],'book_id':['3713327','4074636','26873486'],'rating':['4','4','4'],'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

> 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

> 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