progress.py

import sys


class TxtProgress:
    _tpl = ""

    def __init__(self, template):
        self._tpl = template

    def _syswrite(self, string):
        sys.stdout.write(string)
        sys.stdout.flush()

    def write(self, *args):
        self._syswrite("\r"+(self._tpl % args))

    def cleanup(self):
        self._syswrite("\r\n")

usage.py

progress = TxtProgress("Test: %d -> %d") # define format

for i in range(1, 100):
  progress.write(i, i*i) # update this string corresponding format arguments (like "Test: %d -> %d" % (i, i*i))
progress.cleanup() # normal output will be broken without it