How to get a specific column from a data frame? - pandas

Question

I am working with a data frame, that has three columns: comment_id, class and comment_message, I need to store the three columns, but I am getting an error when I try to store the column called: class, my complete code looks as follows:
from sklearn import svm
import pandas as pd
from sklearn.feature_extraction.text import TfidfVectorizer
df1=pd.read_csv("C:/Users/acamagon/Downloads/dataSet",sep=',')
#print(df1)
comment_id = df1['comment_id']
comment_message = df1['comment_message']
print(comment_message)
here is whe the problem comes:
#Here is the problem
classification = df1['class']
the file looks as follows:
comment_id,comment_message,class
10154395643583692_10154397346673692,quisiera saber el precio y las caracteristicas del selulae samsung s5 xfavoor,1
10154395643583692_10154397434578692,"buenos dias, necesito que le den seguimiento a un telefono que deje en garantia desde octubre en el cac urban center de xalapa, veracruz. ya van 4 veces y me dicen que el telefono no esta y ya va para 3 meses que lo deje. espero me den una respuesta pronto. me comunico al *111 y solo me dicen que el folio sigue en pendiente.",1
10154395643583692_10154397511368692,no sirve su aplicacion de mi telcel... [[PHOTO]],0
10154395643583692_10154397598508692,"buenas tardes, gracias por su atencion brindada... pude resolver mi duda y asi sabre que es lo mejor para mi. saludos.",1
10154394898978692_10154397173938692,q precio tiene el plan????,2
10154394898978692_10154397265133692,para solicitarlo?,1
The error is the following:
---------------------------------------------------------------------------
KeyError Traceback (most recent call last)
C:\Program Files\Anaconda3\lib\site-packages\pandas\indexes\base.py in get_loc(self, key, method, tolerance)
1944 try:
-> 1945 return self._engine.get_loc(key)
1946 except KeyError:
pandas\index.pyx in pandas.index.IndexEngine.get_loc (pandas\index.c:4154)()
pandas\index.pyx in pandas.index.IndexEngine.get_loc (pandas\index.c:4018)()
pandas\hashtable.pyx in pandas.hashtable.PyObjectHashTable.get_item (pandas\hashtable.c:12368)()
pandas\hashtable.pyx in pandas.hashtable.PyObjectHashTable.get_item (pandas\hashtable.c:12322)()
KeyError: 'class'
During handling of the above exception, another exception occurred:
KeyError Traceback (most recent call last)
<ipython-input-54-f52e2494564b> in <module>()
15
16
---> 17 classification = df1['class']
18
19
C:\Program Files\Anaconda3\lib\site-packages\pandas\core\frame.py in __getitem__(self, key)
1995 return self._getitem_multilevel(key)
1996 else:
-> 1997 return self._getitem_column(key)
1998
1999 def _getitem_column(self, key):
C:\Program Files\Anaconda3\lib\site-packages\pandas\core\frame.py in _getitem_column(self, key)
2002 # get column
2003 if self.columns.is_unique:
-> 2004 return self._get_item_cache(key)
2005
2006 # duplicate columns & possible reduce dimensionality
C:\Program Files\Anaconda3\lib\site-packages\pandas\core\generic.py in _get_item_cache(self, item)
1348 res = cache.get(item)
1349 if res is None:
-> 1350 values = self._data.get(item)
1351 res = self._box_item_values(item, values)
1352 cache[item] = res
C:\Program Files\Anaconda3\lib\site-packages\pandas\core\internals.py in get(self, item, fastpath)
3288
3289 if not isnull(item):
-> 3290 loc = self.items.get_loc(item)
3291 else:
3292 indexer = np.arange(len(self.items))[isnull(self.items)]
C:\Program Files\Anaconda3\lib\site-packages\pandas\indexes\base.py in get_loc(self, key, method, tolerance)
1945 return self._engine.get_loc(key)
1946 except KeyError:
-> 1947 return self._engine.get_loc(self._maybe_cast_indexer(key))
1948
1949 indexer = self.get_indexer([key], method=method, tolerance=tolerance)
pandas\index.pyx in pandas.index.IndexEngine.get_loc (pandas\index.c:4154)()
pandas\index.pyx in pandas.index.IndexEngine.get_loc (pandas\index.c:4018)()
pandas\hashtable.pyx in pandas.hashtable.PyObjectHashTable.get_item (pandas\hashtable.c:12368)()
pandas\hashtable.pyx in pandas.hashtable.PyObjectHashTable.get_item (pandas\hashtable.c:12322)()
KeyError: 'class'

Answer 1

Try this:
df1.columns = [c.strip() for c in list(df1.columns.values)]
print(df1["class"])
The problem was that your class header contained whitespace. Stripping that whitespace with .strip() allows pandas to find the header, thus avoiding the KeyError.