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pythonpandasdataframe

Pandas drop first columns after csv read

Is there a way to reference an object within the line of the instantiation ?

See the following example : I wanted to drop the first column (by index) of a csv file just after reading it (usually pd.to_csv outputs the index as first col) :

df = pd.read_csv(csvfile).drop(self.columns[[0]], axis=1)

I understand self should be placed in the object context but it here describes what I intent to do.

(Of course, doing this operation in two separate lines works perfectly.)

Solution

  • One way is to use pd.DataFrame.iloc:

    import pandas as pd
from io import StringIO

mystr = StringIO("""col1,col2,col3
a,b,c
d,e,f
g,h,i
""")

df = pd.read_csv(mystr).iloc[:, 1:]

#   col2 col3
# 0    b    c
# 1    e    f
# 2    h    i