how to drop a range of columns in pandas?

Question

I have a very large dataframe with 108 columns and 8000 rows, and I want to drop some of the columns. It doesn't have a specific column name, it only has index on as column name.

the columns I want to remove is from 74 to 104.

I have tried:

df.drop(['74', '104'], axis = 1, inplace = True)

but it said:

['74' '104'] not found in axis

which 74 and 104 are the column index I want to remove.

How can I fix this problem?

Thank you in advance

Answer 1

When you refer to columns using index, you should treat them as integers.

df.drop([74, 104], axis=1, inplace=True)

Example:

>>> df = pd.DataFrame([[1,2,3],[4,5,6]])
>>> df
   0  1  2
0  1  2  3
1  4  5  6
>>> df.drop([1], axis=1)
   0  2
0  1  3
1  4  6

Answer 2

drop column by index, example:

data= {1:[1,19,20,21,25,29,30,31,30,29,31],
       2: [2,10,20,20,20,10,10,20,20,10,10],
       3: [3,10,20,20,20,10,10,20,20,10,10],
       4: [4,10,20,20,20,10,10,20,20,10,10]}
index= pd.date_range('12/1/2019', periods=11)

df=pd.DataFrame(data, index=index)

df

will give you

            1   2   3   4
2019-12-01  1   2   3   4
2019-12-02  19  10  10  10
2019-12-03  20  20  20  20
2019-12-04  21  20  20  20
2019-12-05  25  20  20  20
2019-12-06  29  10  10  10
2019-12-07  30  10  10  10
2019-12-08  31  20  20  20
2019-12-09  30  20  20  20
2019-12-10  29  10  10  10
2019-12-11  31  10  10  10

and then (say you wish to drop the INDEX of column 0,1,2):

df.drop(df.columns[[0,1,2]], axis=1, inplace=True)

desired result:

            4
2019-12-01  4
2019-12-02  10
2019-12-03  20
2019-12-04  20
2019-12-05  20
2019-12-06  10
2019-12-07  10
2019-12-08  20
2019-12-09  20
2019-12-10  10
2019-12-11  10