如何获取数据框中列的位置编号

Question

我对pandas数据框和列有一个看似简单的问题。假设我有一个带有列的DF：

索引（[＆＃39; _ArtNameName＆＃39;，＆＃39; _BasePrice＆＃39;，＆＃39; _Category＆＃39;，＆＃39; _CategoryName＆＃39;，＆＃39; _DPEffectAdh＆＃39; ，＆＃39; _DPEffectFLAG_AFFAIRES_FNAC＆＃39;，＃DPEffectFin＆＃39;，＆＃39; _DPEffectOff＆＃39;，＆＃39; _DPEffectOpe＆＃39;，＆＃39; _DPEffectSol＆＃39;，＆＃39; _FountQuantity＆＃39;，＆＃39; _LatestBasePrice＆＃39;，＆＃39; _Method＆＃39;，＆＃39; _OptPrice＆＃39;，＆＃39; _OptQuantity＆＃39;，＆＃39; _OwnPriceElasticity＆＃39;， ＆＃39; _PriceLowerBound＆＃39; _＆_39; _PriceUpperBound＆＃39; _QualityIndi​​cator＆＃39;，＆＃39; _Quantity＆＃39;，＆＃39; _Segment＆＃39;，＆＃39; _SegmentName＆ ＃39;，＆＃39; _StatusEstim＆＃39;，＆＃39; _SuccessOptim＆＃39;，＆＃39; _TaxRate＆＃39;，＆＃39; _UnitCost＆＃39;，＆＃39; _StatusOptim＆＃39;]， D型=＆＃39;对象＆＃39）

如何获得说＆＃39; _BasePrice＆＃39;的列位置，例如2，＆＃39; _CategoryName＆＃39;，例如4等？ 谢谢！

Answer 1

使用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

请注意，索引值是从零开始的