Quick and Painless Tutorial (cont)

 # lambda forms
 add = lambda x: x + x
 add(2) # returns 4

 def make_pow() : return lambda x: x * x
 make_pow()(3) # returns 9

 # functional programming: filter, map, reduce
 def f(a): return 'b' <= a <= 'c'
 filter(f, string.split("a b c d")); # return ['b', 'c']

 def split(s): return s[0:len(s)/2]
 map(split, ["aaaaa", "BBBb", "C"]) # returns ['aa', 'BB', '']

 def add(x,y): return x + y
 reduce(add, range(1,10)) # returns 45
 # again, using a lambda
 reduce(lambda x: x + x, range(1,10)) # returns 45

 compilers_file = open('tests/compilers.dat', "r")
 # get a list of compilers (strings), stripped of whitespaces 
 compilers = [string.strip(z) for z in compilers_file.readlines()]