错误：pandas 哈希表 keyerror
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Error: pandas hashtable keyerror
提问by Abhinav Karthick
I have successfully read a csv file using pandas. When I am trying to print the a particular column from the data frame i am getting keyerror. Hereby i am sharing the code with the error.
我已经使用Pandas成功读取了一个 csv 文件。当我尝试从数据框中打印特定列时，我收到了 keyerror。在此，我与错误共享代码。
import pandas as pd
reviews_new = pd.read_csv("D:\aviva.csv")
reviews_new['review']
**
**
reviews_new['review']
Traceback (most recent call last):
File "<ipython-input-43-ed485b439a1c>", line 1, in <module>
reviews_new['review']
File "C:\Users216\AppData\Local\Continuum\Anaconda2\lib\site-packages\pandas\core\frame.py", line 1997, in __getitem__
return self._getitem_column(key)
File "C:\Users216\AppData\Local\Continuum\Anaconda2\lib\site-packages\pandas\core\frame.py", line 2004, in _getitem_column
return self._get_item_cache(key)
File "C:\Users216\AppData\Local\Continuum\Anaconda2\lib\site-packages\pandas\core\generic.py", line 1350, in _get_item_cache
values = self._data.get(item)
File "C:\Users216\AppData\Local\Continuum\Anaconda2\lib\site-packages\pandas\core\internals.py", line 3290, in get
loc = self.items.get_loc(item)
File "C:\Users216\AppData\Local\Continuum\Anaconda2\lib\site-packages\pandas\indexes\base.py", line 1947, in get_loc
return self._engine.get_loc(self._maybe_cast_indexer(key))
File "pandas\index.pyx", line 137, in pandas.index.IndexEngine.get_loc (pandas\index.c:4154)
File "pandas\index.pyx", line 159, in pandas.index.IndexEngine.get_loc (pandas\index.c:4018)
File "pandas\hashtable.pyx", line 675, in pandas.hashtable.PyObjectHashTable.get_item (pandas\hashtable.c:12368)
File "pandas\hashtable.pyx", line 683, in pandas.hashtable.PyObjectHashTable.get_item (pandas\hashtable.c:12322)
KeyError: 'review'
**
**
Can someone help me in this ?
有人可以帮助我吗？
回答by jezrael
I think first is best investigate, what are real columns names, if convert to list better are seen some whitespaces or similar:
我认为首先最好调查一下，什么是真正的列名，如果更好地转换为列表会看到一些空格或类似的：
print (reviews_new.columns.tolist())
I think there can be 2 problems (obviously):
我认为可能有两个问题（显然）：
1.whitespaces in columns names (maybe in data also)
1. 列名中的空格（也可能在数据中）
Solutions are stripwhitespaces in column names:
解决方案是strip列名中的空格：
reviews_new.columns = reviews_new.columns.str.strip()
Or add parameter skipinitialspaceto read_csv:
或添加参数skipinitialspace到read_csv：
reviews_new = pd.read_csv("D:\aviva.csv", skipinitialspace=True)
2.different separator as default ,
2.默认分隔符不同 ,
Solution is add parameter sep:
解决方案是添加参数sep：
#sep is ;
reviews_new = pd.read_csv("D:\aviva.csv", sep=';')
#sep is whitespace
reviews_new = pd.read_csv("D:\aviva.csv", sep='\s+')
reviews_new = pd.read_csv("D:\aviva.csv", delim_whitespace=True)
EDIT:
编辑：
You get whitespace in column name, so need 1.solutions:
您在列名中获得空格，因此需要1.solutions：
print (reviews_new.columns.tolist())
['Name', ' Date', ' review']
^ ^
回答by svp
import pandas as pd
df=pd.read_csv("file.txt", skipinitialspace=True)
df.head()
df['review']
