collatz_quine.py

# 3 10 5 16 8 4 2 1
import sys

def collatz(n):
    out = str(n)
    while n > 1:
        if n % 2 == 1:
            n = n*3 + 1
        else:
            n = n / 2
        out += ' ' + str(n)
    return out

def to_string_literal(s):
    return s.replace('\\', '\\\\').replace('\n','\\n').replace('"', '\\"')

data = "# COLLATZ\nimport sys\n\ndef collatz(n):\n    out = str(n)\n    while n > 1:\n        if n % 2 == 1:\n            n = n*3 + 1\n        else:\n            n = n / 2\n        out += ' ' + str(n)\n    return out\n\ndef to_string_literal(s):\n    return s.replace('\\\\', '\\\\\\\\').replace('\\n','\\\\n').replace('\"', '\\\\\"')\n\ndata = \"DATA\"\n\nstart = int(sys.argv[1])\ndata = data.replace('DATA', to_string_literal(data), 1)\ndata = data.replace('COLLATZ', collatz(start), 1)\nprint data"

start = int(sys.argv[1])
data = data.replace('DATA', to_string_literal(data), 1)
data = data.replace('COLLATZ', collatz(start), 1)
print data