'Error: pandas hashtable keyerror

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.

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:\Users\30216\AppData\Local\Continuum\Anaconda2\lib\site-packages\pandas\core\frame.py", line 1997, in __getitem__
    return self._getitem_column(key)
  File "C:\Users\30216\AppData\Local\Continuum\Anaconda2\lib\site-packages\pandas\core\frame.py", line 2004, in _getitem_column
    return self._get_item_cache(key)
  File "C:\Users\30216\AppData\Local\Continuum\Anaconda2\lib\site-packages\pandas\core\generic.py", line 1350, in _get_item_cache
    values = self._data.get(item)
  File "C:\Users\30216\AppData\Local\Continuum\Anaconda2\lib\site-packages\pandas\core\internals.py", line 3290, in get
    loc = self.items.get_loc(item)
  File "C:\Users\30216\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 ?



Solution 1:[1]

I think first is best investigate, what are real columns names, if convert to list better are seen some whitespaces or similar:

print (reviews_new.columns.tolist())

I think there can be 2 problems (obviously):

1.whitespaces in columns names (maybe in data also)

Solutions are strip whitespaces in column names:

reviews_new.columns = reviews_new.columns.str.strip()

Or add parameter skipinitialspace to read_csv:

reviews_new = pd.read_csv("D:\\aviva.csv", skipinitialspace=True)

2.different separator as default ,

Solution is add parameter 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:

You get whitespace in column name, so need 1.solutions:

print (reviews_new.columns.tolist())
['Name', ' Date', ' review'] 
          ^        ^

Solution 2:[2]

import pandas as pd
df=pd.read_csv("file.txt", skipinitialspace=True)
df.head()
df['review']

Solution 3:[3]

dfObj['Hash Key'] = (dfObj['DEAL_ID'].map(str) +dfObj['COST_CODE'].map(str) +dfObj['TRADE_ID'].map(str)).apply(hash)

#for index, row in dfObj.iterrows():
#        dfObj.loc[`enter code here`index,'hash'] = hashlib.md5(str(row[['COST_CODE','TRADE_ID']].values)).hexdigest()

print(dfObj['hash'])

Sources

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Source: Stack Overflow

Solution Source
Solution 1
Solution 2 svp
Solution 3 Suryakanta Karan