2015-01-09 60 views
4

我在Pandas中做了一个看起来很简单的小组。该列是一个没有NaN或奇怪字符串的字符串列。但是,我不断收到下面的错误。有谁知道为什么这些战斗发生?我觉得喜欢它可能有一些与我的数据,但是这一切似乎是确定...Python pandas groupby pandas.hashtable.PyObjectHashTable.get_item中的关键错误

我正在by_user = df.groupby('User')

和堆栈跟踪:

by_user = df.groupby('User') 
File "c:\Anaconda\lib\site-packages\pandas\core\generic.py", line 2773, in groupby 
sort=sort, group_keys=group_keys, squeeze=squeeze) 
File "c:\Anaconda\lib\site-packages\pandas\core\groupby.py", line 1142, in groupby 
return klass(obj, by, **kwds) 
File "c:\Anaconda\lib\site-packages\pandas\core\groupby.py", line 388, in __init__ level=level, sort=sort) 
File "c:\Anaconda\lib\site-packages\pandas\core\groupby.py", line 2041, in _get_grouper 
gpr = obj[gpr] 
File "c:\Anaconda\lib\site-packages\pandas\core\frame.py", line 1678, in __getitem__ 
return self._getitem_column(key) 
File "c:\Anaconda\lib\site-packages\pandas\core\frame.py", line 1685, in _get  item_column 
return self._get_item_cache(key) 
File "c:\Anaconda\lib\site-packages\pandas\core\generic.py", line 1052, in _ge 
t_item_cache 
values = self._data.get(item) 
File "c:\Anaconda\lib\site-packages\pandas\core\internals.py", line 2565, in get 
loc = self.items.get_loc(item) 
File "c:\Anaconda\lib\site-packages\pandas\core\index.py", line 1181, in get_loc 
return self._engine.get_loc(_values_from_object(key)) 
File "index.pyx", line 129, in pandas.index.IndexEngine.get_loc (pandas\index. 
c:3656) 
File "index.pyx", line 149, in pandas.index.IndexEngine.get_loc (pandas\index. 
c:3534) 
File "hashtable.pyx", line 696, in pandas.hashtable.PyObjectHashTable.get_item 
(pandas\hashtable.c:11911) 
File "hashtable.pyx", line 704, in pandas.hashtable.PyObjectHashTable.get_item 
(pandas\hashtable.c:11864) 
KeyError: 'User' 

df.info():

User Code  175167 non-null object 
Version   175167 non-null object 
Date Accessed 175167 non-null datetime64[ns] 
Series   175167 non-null object 
Software   175167 non-null object 
User    175167 non-null object 
+2

你可以发布'df.info'的输出,也是''User''其中一列? – EdChum 2015-01-09 22:48:24

+0

@EdChum奇怪(?)即使列没有找到,这应该不会引发。 – 2015-01-10 00:00:19

+0

@EdChum我添加了'df.info'。 “用户”在那里,没有空值,它是一个简单的名称集合,而这些名称中没有任何奇怪的字符。这个df是通过'concat'在一堆* .xlsx文件上创建的。 – RedRaven 2015-01-10 05:07:27

回答

6

我[从评论移动] T的容易错过尾随在列名的空白,但你可以手动检查df.columns

>>> df = pd.DataFrame({"User": [1,2]}) 
>>> df2 = pd.DataFrame({"User ": [1,2]}) 
>>> df 
    User 
0  1 
1  2 
>>> df2 
    User 
0  1 
1  2 
>>> df.columns 
Index([u'User'], dtype='object') 
>>> df2.columns 
Index([u'User '], dtype='object') 

(要剥开帷幕了一下,我怀疑这样的事情可能因为当我嘲笑了我自己的数据帧进行回事并看着df.info(),我没有看到你的输出显示的列名和数字之间的空间太多。)