def was_modified_since(header=None, mtime=0, size=0):
"""
Was something modified since the user last downloaded it?
header
This is the value of the If-Modified-Since header. If this is None,
I'll just return True.
mtime
This is the modification time of the item we're talking about.
size
This is the size of the item we're talking about.
"""
try:
if header is None:
raise ValueError
matches = re.match(r"^([^;]+)(; length=([0-9]+))?$", header,
re.IGNORECASE)
header_mtime = parse_http_date(matches.group(1))
header_len = matches.group(3)
if header_len and int(header_len) != size:
raise ValueError
if mtime > header_mtime:
raise ValueError
except (AttributeError, ValueError, OverflowError):
return True
return False
def testParsingAsctime(self):
parsed = parse_http_date('Sun Nov 6 08:49:37 1994')
self.assertEqual(datetime.utcfromtimestamp(parsed),
datetime(1994, 11, 6, 8, 49, 37))
def testParsingRfc850(self):
parsed = parse_http_date('Sunday, 06-Nov-94 08:49:37 GMT')
self.assertEqual(datetime.utcfromtimestamp(parsed),
datetime(1994, 11, 6, 8, 49, 37))
