Partially renaming columns in Pandas DataFrame
I am trying to rename the first N columns of a DataFrame.
import pandas as pd
Dat = pd.read_csv(inputName, delimiter='\t', header=0)
The original table looks like this:
$Date $ciq_ticker $industry price ...
'09/30/2016 'AAPL' 'Technology' 100.00
'09/30/2016 'AMZN' 'Consumer' 1000.00
...
I want some of the column names to be more intuitive. That something like this is in my mind:
descriptors = ['date','ticker','industry']
Dat.columns[:len(descriptors)] = descriptors
This gives the error "Index does not support volatile operations".
I know this works:
Dat.rename(columns={'$Date': 'date', '$ciq_ticker': 'ticker', '$industry': 'industry'}, inplace=True)
But I just don't like the idea of explicitly entering the original column names. True, the real table contains over 20 columns that I need to change.
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1 answer
Try the following:
In [91]: cols = ['date','ticker','industry']
In [92]: df
Out[92]:
$Date $ciq_ticker $industry price
0 09/30/2016 AAPL Technology 100.0
1 09/30/2016 AMZN Consumer 1000.0
In [93]: df.columns = cols + df.columns.tolist()[len(cols):]
In [94]: df
Out[94]:
date ticker industry price
0 09/30/2016 AAPL Technology 100.0
1 09/30/2016 AMZN Consumer 1000.0
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