import random
import string
import sys

def random_string(s):
    return ''.join([random.choice(string.letters) for i in range(s)])

def make_test_file(pickler, n):
    """Create a dictionary from 1-tuple of string to ints, and pickle it 
    using module pickler. The strings are created randomly, giving a 
    dictionary of maximum size n.     
    """
    
    # Since the dict is filled with random keys, its size may be smaller 
    # than n, as some random keys may match.
    # for keys containing a 5 letter random string, and n = 1e6,
    # the actual dictionary size is expected to be only 0.1% smaller.

    d = dict([((random_string(5), ), i) for i in range(n)])

    pickle = __import__(pickler)

    with open("test.pickle", 'wb') as handle:
        pickle.dump(d, handle, 2)


if __name__ == "__main__":
    
    # usage: python2.x make_file.py pickler n
    
    pickler = sys.argv[1] # name of pickle module to use (pickle or cPickle)
    n = int(sys.argv[2]) # size of dictionary
    make_test_file(pickler, n)