python - Getting the integer index of a Pandas DataFrame row fulfilling a condition? -

i have following dataframe:

    b  c b 2  1  2  3 5  4  5  6 

as can see, column b used index. want ordinal number of row fulfilling ('b' == 5), in case 1.

the column being tested can either index column (as b in case) or regular column, e.g. may want find index of row fulfilling ('c' == 6).

you use np.where this:

import pandas pd import numpy np df = pd.dataframe(np.arange(1,7).reshape(2,3),                   columns = list('abc'),                    index=pd.series([2,5], name='b')) print(df) #     b  c # b          # 2  1  2  3 # 5  4  5  6 print(np.where(df.index==5)[0]) # [1] print(np.where(df['c']==6)[0]) # [1] 

the value returned array since there more 1 row particular index or value in column.