Find all legendary creatures with a particular colour identity

tinyleaders.py

from itertools import *

colours = 'WUR'

def f(c):
    return 'o:{' + str(c) + '}'

def g(c):
    return c.lower()

def h(z):
    q = list(z)
    numcolours = len(filter(lambda x: len(x) != 0, q))
    if numcolours == 0:
        return 'c:c'
    elif numcolours == 1:
        return 'c!' + ''.join(q)
    return 'c!m' + ''.join(q)

queries = []
for c in product({0,1}, repeat=len(colours)):
    z = (g(colours[i]) if b else '' for (i, b) in enumerate(int(not x) for x in c))
    query = "cmc<4 t:legendary t:creature " + h(z) + ' '
    y = (f(colours[i]) if b else '' for (i, b) in enumerate(c))
    query += '(' + ' AND '.join(filter(lambda x: len(x) != 0, y)) + ')'

    queries.append(query)
    
import httplib
import urllib
import re

for q in queries:
    conn = httplib.HTTPConnection("magiccards.info")
    url = urllib.quote(q)
    conn.request("GET", "/query?q=" + url[:-3])
    r = conn.getresponse()
    if not re.search('Your query did not match any cards.',  r.read()):
        print(q)