Diff-char.py

import xml.etree.cElementTree as ET
import pprint
import re
lower = re.compile(r'^([a-z]|_)*$')
lower_colon = re.compile(r'^([a-z]|_)*:([a-z]|_)*$')
problemchars = re.compile(r'[=\+/&<>;\'"\?%#$@\,\. \t\r\n]')


def key_type(element, keys):
    if element.tag == "tag":
            if lower.search(element.attrib['k']):
              keys["lower"] += 1
            elif lower_colon.search(element.attrib['k']):
              keys["lower_colon"] += 1
            elif problemchars.search(element.attrib['k']):
              keys["problemchars"] += 1
            else:
              keys["other"] += 1
    return keys



def process_map(filename):
    keys = {"lower": 0, "lower_colon": 0, "problemchars": 0, "other": 0}
    for _, element in ET.iterparse(filename):
        keys = key_type(element, keys)

    return keys
keys = process_map('mumbai_sample.osm')
pprint.pprint(keys)