Pandas Select DataFrame columns using boolean

Question

I want to use a boolean to select the columns with more than 4000 entries from a dataframe comb which has over 1,000 columns. This expression gives me a Boolean

Answer 1

Another solution is to transpose comb to make its columns act as its index, then transpose on the resulting subset:

comb.T[criteria].T

Again, not particularly elegant, but at least shorter/less repetitive than the leading solution.