Pandas Column and Filter Subset

Question

Using Pandas, as I will filter the rows and take only a subset of the columns from the Pandas frame, please, in one command.

I am trying to apply something like this ....

frame[(frame.DESIGN_VALUE > 20) & (frame['mycol3','mycol6']))]

Thanks.

Answer 1

You can use the logical condition to create a mask and pass a list of quantities of interest using loc:

frame.loc[frame['DESIGN_VALUE'] > 20,['mycol3', 'mycol6']]

I advise above because it means that you are working with a view, not a copy, and secondly, I also strongly suggest using it []to select columns, and not as attributes using the sot operator, .this avoids the ambiguity in the behavior of pandas

:

In [184]:
df = pd.DataFrame(columns = list('abc'), data = np.random.randn(5,3))
df

Out[184]:
          a         b         c
0 -0.628354  0.833663  0.658212
1  0.032443  1.062135 -0.335318
2 -0.450620 -0.906486  0.015565
3  0.280459 -0.375468 -1.603993
4  0.463750 -0.638107 -1.598261

In [187]:
df.loc[df['a']>0, ['b','c']]

Out[187]:
          b         c
1  1.062135 -0.335318
3 -0.375468 -1.603993
4 -0.638107 -1.598261

:

frame[(frame.DESIGN_VALUE > 20) & (frame['mycol3','mycol6']))]

, - df , , &

Answer 2

, ')'

frame[(frame.DESIGN_VALUE > 20) & (frame['mycol3','mycol6']))]

:

frame[(frame.DESIGN_VALUE > 20) & (frame['mycol3','mycol6'])]