On Apr 22, 2007, at 4:08 PM, proctor wrote: > On Apr 22, 2:55 pm, [EMAIL PROTECTED] wrote: >> On Apr 22, 11:49 am, proctor <[EMAIL PROTECTED]> wrote: >> >> >> >>> hello, >> >>> i have a small function which mimics binary counting. it runs >>> fine as >>> long as the input is not too long, but if i give it input longer >>> than >>> 8 characters it gives >> >>> RuntimeError: maximum recursion depth exceeded in cmp >> >>> i'm not too sure what i am doing improperly. is there really a >>> lot of >>> recursion in this code? >> >>> ================== >> >>> import sys >> >>> def ch4(item, n=0): >>> if n < len(item): >>> if item[n] == '0': >>> item[n] = '1' >>> print ''.join(item) >>> ch4(item) >>> elif item[n] == '1': >>> item[n] = '0' >>> ch4(item, n+1) >> >>> ch4(list(sys.argv[1])) >> >>> ================== >> >>> this function expects input in the form of a string of zeros, like >>> this: >> >>> python test-bin.py 00000000 >> >>> and is expected to output a list of permutations like this: >> >>> $ python test-bin.py 0000 >>> 1000 >>> 0100 >>> 1100 >>> 0010 >>> 1010 >>> 0110 >>> 1110 >>> 0001 >>> 1001 >>> 0101 >>> 1101 >>> 0011 >>> 1011 >>> 0111 >>> 1111 >> >>> thanks for all help! >> >>> sincerely, >>> proctor >> >> If you just want to make it work as is....check >> >> sys.setrecursionlimit() >> >> ~Sean > > very nice. thanks sean. so is the structure of my original code > unrescuable? i cannot rearrange it to bypass the recursion? >
Anything that can be done with recursion can be done without recursion. If you really wanted to mimic a binary counter, why not write a function that converts a number to binary? Then you could just count up from 0, printing the return from your binary conversion function... And the binary converter would be pretty easy too: just think of it as making change -- for a given number you just divide the number by each of [2 ** x for x in range(len(sys.argv[1]), 0, -1)] and append the string representations of the answers to a list and if the answer is 1, subtract that much from the number... -- http://mail.python.org/mailman/listinfo/python-list
