I suspect the function I sent out earlier, using octal conversion and a lookup table, will be faster. But it would be very interesting to see some simple benchmarks.
On Feb 20, 2007, at 10:47 PM, Dick Moores wrote: > I was surprised to be unable to find a function in Python for > converting ints from base10 to base2. Is there one? > > I wrote one, but have I reinvented the wheel again? (Even if I have, > it was an interesting exercise for me.) > > I know some of you CS people won't like what I do with negative ints, > but I wanted it this way. On other points than that, I'd appreciate > criticism/suggestions. > > =========================================================== > def computeBin(n): > """converts base10 integer n to base2 b as string""" > from math import log, floor > sign = '' > if n == 0: > b = '0' > else: > if n < 0: > sign = "-" > n = -n > e = int(floor(log(n,2))) > b = '1' > > for x in range(e): > r = n % 2**e > if r >= 2**(e-1): > b += '1' > else: > b += '0' > e -= 1 > return sign + b > > def printResult(n,b): > print "%d is %s" % (n, b) > > def confirmResult(n,b): > print "Confirming using int():" > print "int(%s,2) is %s" % (b, int(b,2)) > > if __name__ == '__main__': > n = 1234567890 > b = computeBin(n) > printResult(n,b) > confirmResult(n,b) > ============================================== > > Dick Moores > > _______________________________________________ > Tutor maillist - Tutor@python.org > http://mail.python.org/mailman/listinfo/tutor -- -dave---------------------------------------------------------------- After all, it is not *that* inexpressible. -H.H. The Dalai Lama _______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
