refactor(ruff): multiple changes to clear ruff issues Fix a couple of missing returns of booleans for security checks. Turns an implicit return None into an explicit return False. Fix loop index variable being reassigned inside loop by renaming index variable. 2 instances. Consolidate 2 isinstance calls to 1 with tuple class argument. Replace dict(list comprehension) with dict conprehension. Variable renames. Removal of unused variable. Whitespace fixes. sort imports

#!/usr/bin/env python

# Roundup requires Python 2.7+ as mentioned in doc\installation.txt
from __future__ import print_function
import sys

VERSION_NEEDED = (2, 7)

if sys.version_info < VERSION_NEEDED:
    print("Content-Type: text/plain\n")
    print("Roundup requires Python %s.%s or newer." % VERSION_NEEDED)
    sys.exit(0)