Drop NaNs

R::

TODO

pandas:

mtcars[~pd.isnull(mtcars.cyl)]

pandas:

mtcars.dropna(subset=['cyl'])

plydata:

mtcars >> dp.call('.dropna', subset=['cyl'])

dpylython:

dp.DplyFrame(mtcars) >> dp.sift(~X.cyl.isnull())

dfply:

mtcars >>dp.filter_by(~X.cyl.isnull())

but beware the inversion bug

dppd:

dp(mtcars).filter_by(~X.cyl.isnull()).pd
or
dp(mtcars).dropna(subset=['cyl']).pd