NaN and non python-variable column name

Prelude:

mtcars = mtcars.assign(**{'da cyl': mtcars.cyl})

R:

mtcars = mtcars %>% mutate(`da cyl` = cyl)
mtcars %>% filter(!is.nan(cyl))

pandas:

mtcars[mtcars['da cyl'].isnull()]

plydata:

query supports no Q ('variable escape function') (bug?)

dpylython:

dp.DplyFrame(mtcars) >> dp.sift(~X['da cyl'].isnull())

dfply:

mtcars >> dp.filter_by(~X['da cyl'].isnull())

dppd:

dp(mtcars).filter_by(~X['da cyl'].isnull()).pd