Python Forum
Difference of two columns in Pandas dataframe - Printable Version

+- Python Forum (https://python-forum.io)
+-- Forum: Python Coding (https://python-forum.io/forum-7.html)
+--- Forum: Data Science (https://python-forum.io/forum-44.html)
+--- Thread: Difference of two columns in Pandas dataframe (/thread-27277.html)

Difference of two columns in Pandas dataframe - zinho - Jun-01-2020

Hi I tring to get two columns from Excel and parse to a DataFrame, after I need subtract this columns.

        
    ndf = xw.Range('AI1:AJ' + str(len(last_row))).options(pd.DataFrame).value

    #Error in this line below
    ndf['VC-BC'] = ndf['VC'] - ndf['BC']
    
    #xw.Range("BH1").options(index=False).value = ndf

    print(ndf.head(20))
After run code error appear
Error:
C:\Users\alexandre.goncalves>C:/Users/alexandre.goncalves/AppData/Local/Programs
/Python/Python38-32/python.exe c:/Users/zinho/Downloads/projetos/f
at_vfour.py
Traceback (most recent call last):
  File "C:\Users\zinho\AppData\Local\Programs\Python\Python38-32\lib\site-packages\pandas\core\indexes\base.py", line 2646, in get_loc
    return self._engine.get_loc(key)
  File "pandas\_libs\index.pyx", line 111, in pandas._libs.index.IndexEngine.get_loc
  File "pandas\_libs\index.pyx", line 138, in pandas._libs.index.IndexEngine.get_loc
  File "pandas\_libs\hashtable_class_helper.pxi", line 1618, in pandas._libs.hashtable.PyObjectHashTable.get_item
  File "pandas\_libs\hashtable_class_helper.pxi", line 1626, in pandas._libs.hashtable.PyObjectHashTable.get_item
KeyError: 'VC'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "c:/Users/zinho/Downloads/projetos/fat_vfour.py", line 90, in <module>
    ndf['VC-BC'] = ndf['VC'] - ndf['BC']
  File "C:\Users\zinho\AppData\Local\Programs\Python\Python38-32\lib\site-packages\pandas\core\frame.py", line 2800, in __getitem__
    indexer = self.columns.get_loc(key)
  File "C:\Users\zinho\AppData\Local\Programs\Python\Python38-32\lib\site-packages\pandas\core\indexes\base.py", line 2648, in get_loc
    return self._engine.get_loc(self._maybe_cast_indexer(key))
  File "pandas\_libs\index.pyx", line 111, in pandas._libs.index.IndexEngine.get_loc
  File "pandas\_libs\index.pyx", line 138, in pandas._libs.index.IndexEngine.get_loc
  File "pandas\_libs\hashtable_class_helper.pxi", line 1618, in pandas._libs.hashtable.PyObjectHashTable.get_item
  File "pandas\_libs\hashtable_class_helper.pxi", line 1626, in pandas._libs.hashtable.PyObjectHashTable.get_item
KeyError: 'VC'
If try show my new dataframe display like this.
Output:
             BC
VC
1845.60    0.00
963.72     0.00
1898.00    0.00
15.43      5.56
8.07       2.91
4.99       1.79
41.18     14.75
34.14     12.30
77.32     21.65
107.28   107.28
7.00       2.51
18.50      6.63
6.88       2.47
19.39      6.95
27.96     10.08
51.55     14.43
26.86      9.62
108.02    38.93
98.10     35.15
108.85    39.23


RE: Difference of two columns in Pandas dataframe - zinho - Jun-17-2020

Hi any help?

this is my cross-post
https://stackoverflow.com/questions/62429862/difference-of-two-columns-in-pandas-dataframe

RE: Difference of two columns in Pandas dataframe - zinho - Jun-17-2020

My question is solved now, thank you
I miss this
ndf = xw.Range('AI1:AJ' + str(len(last_row))).options(pd.DataFrame).value
Would be this
ndf = xw.Range('AI1:AJ' + str(len(last_row))).options(pd.DataFrame, index=False).value