Hackathon r2-7

7.py

input = "\x4c\x9a\x59\x3a\x35\x89\x91\x24\x5a\x9a\x5d\x3a\x35\x29\x95\x2b\x53\x8c\x35\xba\x94\xca\xd5\x2d\x4d\xae\x59\x92\x45\x6a\xd1\x21\x4c\x9a\x59"
#input="\x53\xac\x3d\x7a\xc4"
pos = 0
out=""
for i in input:
	# do a circular right shift
	b = list(bin(ord(i)).split("0b")[1])
	# pad to 8 bits
	while len(b) < 8:
		b.insert(0, "0")
	print pos, b
	i=0
	# right shift
	while i < pos:
		b.insert(0, b.pop())
		i += 1
	print b
	pos += 1
	decoded =  chr(int("".join(b), 2))
	# reverse it!
	i=0
	start = 65
	end = 90
	while i <= 26:
		if decoded == chr(start+i):
			decoded = chr(end-i)
			break
		i += 1
	out += decoded
print out

great

I use collections:deque to rotate (right shift)

from collections import deque
d=deque("11110000")
d.rotate(4)
d
deque(['0', '0', '0', '0', '1', '1', '1', '1'])
list(d)
['0', '0', '0', '0', '1', '1', '1', '1']