def easy(url_str):
    import re
    patt = re.compile(r':\w+/?')
    matches = patt.findall(url_str)
    for match in matches:
        var = match[1:-1]
        var_re = r'(?P<%s>.*)/' % var
        url_str = url_str.replace(match, var_re)
    url_str += '$'
    return url_str

# usage:
# urlpatterns = patterns('',
#     url(easy('calendar/:year/:month/'), 'apps.events.views.calendar'),
# )

# output:
# urlpatterns = patterns('',
#     url(r'^calendar/(?P<year>.*)/(?P<month>.*)$', 'apps.events.views.calendar'),
# )

# so much win !