5

这是一个简单的问题，在网上很难找到答案。情况如下：

>>> A
[('hey', 'you', 4), ('hey', 'not you', 5), ('not hey', 'you', 2), ('not hey', 'not you', 6)]
>>> A_p = pandas.DataFrame(A)
>>> A_p
         0        1  2
0      hey      you  4
1      hey  not you  5
2  not hey      you  2
3  not hey  not you  6
>>> B_p = A_p.pivot(0,1,2)
>>> B_p
1        not you  you
0                    
hey            5    4
not hey        6    2

这并不是文档中所建议的pivot——在那里，它显示了左上角没有 1 和 0 的结果。这就是我正在寻找的，一个打印为的 DataFrame 对象

         not you  you
hey            5    4
not hey        6    2

问题是正常行为会导致 csv 文件的第一行是

0,not you,you

当我真的想要

not you, you

当普通的 csv 文件（带有前面的“0”）读入 R 时，它没有正确设置框架对象的列名和行名，导致痛苦的手动操作以获取正确的格式。有没有办法让枢轴给我一个 DataFrame 对象，而左上角没有额外的信息？

4

1 回答 1

4

好吧，你有：

In [17]: B_p.to_csv(sys.stdout)
0,not you,you
hey,5.0,4.0
not hey,6.0,2.0

In [18]: B_p.to_csv(sys.stdout, index=False)
not you,you
5.0,4.0
6.0,2.0

但我假设你想要行名。将索引名称设置为 None ( B_p.index.name = None) 会给出一个前导逗号：

In [20]: B_p.to_csv(sys.stdout)
,not you,you
hey,5.0,4.0
not hey,6.0,2.0

write.csv这大致匹配（忽略带引号的字符串）R 在when中写入的内容row.names=TRUE：

"","a","b"
"foo",0.720538259472741,-0.848304940318957
"bar",-0.64266667412325,-0.442441171401282
"baz",-0.419181615269841,-0.658545964124229
"qux",0.881124313748992,0.36383198969179
"bar2",-1.35613767310069,-0.124014006180608

这些有帮助吗？

编辑：index_label=False今天添加了您想要的选项：

In [2]: df
Out[2]: 
       A  B
one    1  4
two    2  5
three  3  6

In [3]: df.to_csv('foo.csv', index_
index_exp     index_label=  index_name=   

In [3]: df.to_csv('foo.csv', index_name=False)

In [4]: 
11:24 ~/code/pandas  (master)$ R

R version 2.14.0 (2011-10-31)
Copyright (C) 2011 The R Foundation for Statistical Computing
ISBN 3-900051-07-0
Platform: x86_64-unknown-linux-gnu (64-bit)

R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type 'license()' or 'licence()' for distribution details.

  Natural language support but running in an English locale

R is a collaborative project with many contributors.
Type 'contributors()' for more information and
'citation()' on how to cite R or R packages in publications.

Type 'demo()' for some demos, 'help()' for on-line help, or
'help.start()' for an HTML browser interface to help.
Type 'q()' to quit R.

[Previously saved workspace restored]

re> read.csv('foo.csv')
      A B
one   1 4
two   2 5
three 3 6
于 2012-06-21T15:31:58.657 回答