how to get the position number of a column in a data frame

Question

I have a seemingly simple (?) question on pandas data frames and columns. Say I have a DF with columns :

Index(['_ArticleName', '_BasePrice', '_Category', '_CategoryName', '_DPEffectAdh', '_DPEffectFLAG_AFFAIRES_FNAC', '_DPEffectFin', '_DPEffectOff', '_DPEffectOpe', '_DPEffectSol', '_FittedQuantity', '_LatestBasePrice', '_Method', '_OptPrice', '_OptQuantity', '_OwnPriceElasticity', '_PriceLowerBound', '_PriceUpperBound', '_QualityIndicator', '_Quantity', '_Segment', '_SegmentName', '_StatusEstim', '_SuccessOptim', '_TaxRate', '_UnitCost', '_StatusOptim'], dtype='object')

How do I get the column position of say '_BasePrice', eg 2, '_CategoryName', eg 4, etc? Thanks!

Answer 1

Use get_loc :

In [46]:
df = pd.DataFrame({'B':randn(5), 'A':randn(5), 'F':randn(5), 'D':randn(5)})

df.columns
Out[46]:
Index(['A', 'B', 'D', 'F'], dtype='object')
In [47]:
df.columns.get_loc('D')
Out[47]:
2

In [48]:
df = pd.DataFrame(columns=['_ArticleName', '_BasePrice', '_Category', '_CategoryName', '_DPEffectAdh', '_DPEffectFLAG_AFFAIRES_FNAC', '_DPEffectFin', '_DPEffectOff', '_DPEffectOpe', '_DPEffectSol', '_FittedQuantity', '_LatestBasePrice', '_Method', '_OptPrice', '_OptQuantity', '_OwnPriceElasticity', '_PriceLowerBound', '_PriceUpperBound', '_QualityIndicator', '_Quantity', '_Segment', '_SegmentName', '_StatusEstim', '_SuccessOptim', '_TaxRate', '_UnitCost', '_StatusOptim'])

df.columns
Out[48]:
Index(['_ArticleName', '_BasePrice', '_Category', '_CategoryName', '_DPEffectAdh', '_DPEffectFLAG_AFFAIRES_FNAC', '_DPEffectFin', '_DPEffectOff', '_DPEffectOpe', '_DPEffectSol', '_FittedQuantity', '_LatestBasePrice', '_Method', '_OptPrice', '_OptQuantity', '_OwnPriceElasticity', '_PriceLowerBound', '_PriceUpperBound', '_QualityIndicator', '_Quantity', '_Segment', '_SegmentName', '_StatusEstim', '_SuccessOptim', '_TaxRate', '_UnitCost', '_StatusOptim'], dtype='object')
In [49]:

df.columns.get_loc('_BasePrice')
Out[49]:
1

In [50]:
df.columns.get_loc('_CategoryName')

Out[50]:
3

Note that index values are zero-based