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#!/usr/bin/env python
"""
This example shows how to use the function generate_hash.
generate_hash(kdic, Hash)
returns hash functions f1 and f2, and G for a perfect minimal hash.
Input is dictionary 'kdic' with the keys and desired hash values.
'Hash' is a random hash function generator, that means Hash(N) returns a
returns a random hash function which returns hash values from 0..N-1.
"""
import sys
import random, string
sys.path.append('..')
from perfect_hash import generate_hash
month = dict(zip('jan feb mar apr may jun jul aug sep oct mov dec'.split(),
range(1, 13)))
def mkRandHash(N):
"""
Return a random hash function which returns hash values from 0..N-1.
"""
junk = "".join(random.choice(string.letters + string.digits)
for i in xrange(10))
return lambda key: hash(junk + str(key)) % N
f1, f2, G = generate_hash(month, mkRandHash)
for k, h in month.items():
assert h == ( G[f1(k)] + G[f2(k)] ) % len(G)
print 'OK'
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