Getting a list of indices where pandas boolean series is True
Also works:
s.where(lambda x: x).dropna().index, and
it has the advantage of being easy to chain pipe - if your series is being computed on the fly, you don't need to assign it to a variable.
Note that if s is computed from r: s = cond(r)
than you can also use: r.where(lambda x: cond(x)).dropna().index.
I have a pandas series with boolean entries.  I would like to get a list of indices where the values are True.
For example the input pd.Series([True, False, True, True, False, False, False, True])
should yield the output [0,2,3,7].
I can do it with a list comprehension, but is there something cleaner or faster?