Convert smart markdown to dumb markdown

dumbdowner.py

#!/usr/bin/env python3
import sys

if sys.version_info[0] != 3:
    sys.exit("Must use python3")

replacements = {0x2013: '--',
                0x2014: '---',
                0x201c: '"',
                0x201d: '"',
                0x2018: "'",
                0x2019: "'",
                0x2026: '...',
                0xa0: ' '}

text = sys.stdin.read()
for r in replacements:
    text = text.replace(chr(r), replacements[r])

print(text)