It's best not to recreate functionality that is already in the standard library.
Take a look at the standard library module itertools
. Particularly the combinations()
, permutations()
, and product()
functions.
import itertools
lower_a = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']
upper_a = ['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z']
num = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9']
all = lower_a + upper_a + num
for r in range(1, 3):
for s in itertools.product(all, repeat=r):
print ''.join(s)
If your version of Python is old you may not have access to these functions. However if you take a look in the documentation for Python 2.6, you can see how all of these functions can be implemented in Python. For instance, the implementation of itertools.product
is given as:
def product(*args, **kwds):
# product('ABCD', 'xy') --> Ax Ay Bx By Cx Cy Dx Dy
# product(range(2), repeat=3) --> 000 001 010 011 100 101 110 111
pools = map(tuple, args) * kwds.get('repeat', 1)
result = [[]]
for pool in pools:
result = [x+[y] for x in result for y in pool]
for prod in result:
yield tuple(prod)
You could also try a recursive solution instead:
lower_a = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']
upper_a = ['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z']
num = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9']
all = lower_a + upper_a + num
def recursive_product(myList, length, myString = ""):
if length == 0:
print myString
return
for c in myList:
recursive_product(myList, length-1, myString + c)
for r in range(1, 3):
recursive_product(all, r)