Dataframe KeyError:

Question

This is my data frame code:

result = pd.read_csv("learning_1.csv")

Then when I want to check the diagnosis it turns out that it showed key error

result["Diagnosis"]

It show KeyError: 'Diagnosis'.

    KeyError                                  Traceback (most recent call last)
<ipython-input-119-76b8b4a21668> in <module>
----> 1 result["Diagnosis"]

c:\python\python3.8\lib\site-packages\pandas\core\frame.py in __getitem__(self, key)
   2798             if self.columns.nlevels > 1:
   2799                 return self._getitem_multilevel(key)
-> 2800             indexer = self.columns.get_loc(key)
   2801             if is_integer(indexer):
   2802                 indexer = [indexer]

c:\python\python3.8\lib\site-packages\pandas\core\indexes\base.py in get_loc(self, key, method, tolerance)
   2646                 return self._engine.get_loc(key)
   2647             except KeyError:
-> 2648                 return self._engine.get_loc(self._maybe_cast_indexer(key))
   2649         indexer = self.get_indexer([key], method=method, tolerance=tolerance)
   2650         if indexer.ndim > 1 or indexer.size > 1:

pandas\_libs\index.pyx in pandas._libs.index.IndexEngine.get_loc()

pandas\_libs\index.pyx in pandas._libs.index.IndexEngine.get_loc()

pandas\_libs\hashtable_class_helper.pxi in pandas._libs.hashtable.PyObjectHashTable.get_item()

pandas\_libs\hashtable_class_helper.pxi in pandas._libs.hashtable.PyObjectHashTable.get_item()

KeyError: 'Diagnosis'

Answer 1

Maybe there is some space or hidden character in the column name.

Try excecuting "result.columns" and see the output.