Python中mapfilterreduce的递归实现:map2=lambda f,seq: [] if seq==[] else [f(seq[0])] + map2(f, seq[1:]) filter2=lambda f, seq: [] if seq==[] else ( [seq[0]]+filter2(f, seq[1:]) if f(seq[0]) else filter2(f, seq[1:]) ) reduce2=lambda f,seq,x: x if seq==[] else reduce2(f, seq[1