"""Utility functions and date/time routines. Copyright 2002-2006 John J Lee This code is free software; you can redistribute it and/or modify it under the terms of the BSD or ZPL 2.1 licenses (see the file COPYING.txt included with the distribution). """ import re, time, warnings class ExperimentalWarning(UserWarning): pass def experimental(message): warnings.warn(message, ExperimentalWarning, stacklevel=3) def hide_experimental_warnings(): warnings.filterwarnings("ignore", category=ExperimentalWarning) def reset_experimental_warnings(): warnings.filterwarnings("default", category=ExperimentalWarning) def deprecation(message): warnings.warn(message, DeprecationWarning, stacklevel=3) def hide_deprecations(): warnings.filterwarnings("ignore", category=DeprecationWarning) def reset_deprecations(): warnings.filterwarnings("default", category=DeprecationWarning) def isstringlike(x): try: x + "" except: return False else: return True ## def caller(): ## try: ## raise SyntaxError ## except: ## import sys ## return sys.exc_traceback.tb_frame.f_back.f_back.f_code.co_name from calendar import timegm # Date/time conversion routines for formats used by the HTTP protocol. EPOCH = 1970 def my_timegm(tt): year, month, mday, hour, min, sec = tt[:6] if ((year >= EPOCH) and (1 <= month <= 12) and (1 <= mday <= 31) and (0 <= hour <= 24) and (0 <= min <= 59) and (0 <= sec <= 61)): return timegm(tt) else: return None days = ["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"] months = ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"] months_lower = [] for month in months: months_lower.append(month.lower()) def time2isoz(t=None): """Return a string representing time in seconds since epoch, t. If the function is called without an argument, it will use the current time. The format of the returned string is like "YYYY-MM-DD hh:mm:ssZ", representing Universal Time (UTC, aka GMT). An example of this format is: 1994-11-24 08:49:37Z """ if t is None: t = time.time() year, mon, mday, hour, min, sec = time.gmtime(t)[:6] return "%04d-%02d-%02d %02d:%02d:%02dZ" % ( year, mon, mday, hour, min, sec) def time2netscape(t=None): """Return a string representing time in seconds since epoch, t. If the function is called without an argument, it will use the current time. The format of the returned string is like this: Wed, DD-Mon-YYYY HH:MM:SS GMT """ if t is None: t = time.time() year, mon, mday, hour, min, sec, wday = time.gmtime(t)[:7] return "%s %02d-%s-%04d %02d:%02d:%02d GMT" % ( days[wday], mday, months[mon - 1], year, hour, min, sec) UTC_ZONES = {"GMT": None, "UTC": None, "UT": None, "Z": None} timezone_re = re.compile(r"^([-+])?(\d\d?):?(\d\d)?$") def offset_from_tz_string(tz): offset = None if UTC_ZONES.has_key(tz): offset = 0 else: m = timezone_re.search(tz) if m: offset = 3600 * int(m.group(2)) if m.group(3): offset = offset + 60 * int(m.group(3)) if m.group(1) == '-': offset = -offset return offset def _str2time(day, mon, yr, hr, min, sec, tz): # translate month name to number # month numbers start with 1 (January) try: mon = months_lower.index(mon.lower()) + 1 except ValueError: # maybe it's already a number try: imon = int(mon) except ValueError: return None if 1 <= imon <= 12: mon = imon else: return None # make sure clock elements are defined if hr is None: hr = 0 if min is None: min = 0 if sec is None: sec = 0 yr = int(yr) day = int(day) hr = int(hr) min = int(min) sec = int(sec) if yr < 1000: # find "obvious" year cur_yr = time.localtime(time.time())[0] m = cur_yr % 100 tmp = yr yr = yr + cur_yr - m m = m - tmp if abs(m) > 50: if m > 0: yr = yr + 100 else: yr = yr - 100 # convert UTC time tuple to seconds since epoch (not timezone-adjusted) t = my_timegm((yr, mon, day, hr, min, sec, tz)) if t is not None: # adjust time using timezone string, to get absolute time since epoch if tz is None: tz = "UTC" tz = tz.upper() offset = offset_from_tz_string(tz) if offset is None: return None t = t - offset return t strict_re = re.compile(r"^[SMTWF][a-z][a-z], (\d\d) ([JFMASOND][a-z][a-z]) " r"(\d\d\d\d) (\d\d):(\d\d):(\d\d) GMT$") wkday_re = re.compile( r"^(?:Sun|Mon|Tue|Wed|Thu|Fri|Sat)[a-z]*,?\s*", re.I) loose_http_re = re.compile( r"""^ (\d\d?) # day (?:\s+|[-\/]) (\w+) # month (?:\s+|[-\/]) (\d+) # year (?: (?:\s+|:) # separator before clock (\d\d?):(\d\d) # hour:min (?::(\d\d))? # optional seconds )? # optional clock \s* ([-+]?\d{2,4}|(?![APap][Mm]\b)[A-Za-z]+)? # timezone \s* (?:\(\w+\))? # ASCII representation of timezone in parens. \s*$""", re.X) def http2time(text): """Returns time in seconds since epoch of time represented by a string. Return value is an integer. None is returned if the format of str is unrecognized, the time is outside the representable range, or the timezone string is not recognized. If the string contains no timezone, UTC is assumed. The timezone in the string may be numerical (like "-0800" or "+0100") or a string timezone (like "UTC", "GMT", "BST" or "EST"). Currently, only the timezone strings equivalent to UTC (zero offset) are known to the function. The function loosely parses the following formats: Wed, 09 Feb 1994 22:23:32 GMT -- HTTP format Tuesday, 08-Feb-94 14:15:29 GMT -- old rfc850 HTTP format Tuesday, 08-Feb-1994 14:15:29 GMT -- broken rfc850 HTTP format 09 Feb 1994 22:23:32 GMT -- HTTP format (no weekday) 08-Feb-94 14:15:29 GMT -- rfc850 format (no weekday) 08-Feb-1994 14:15:29 GMT -- broken rfc850 format (no weekday) The parser ignores leading and trailing whitespace. The time may be absent. If the year is given with only 2 digits, the function will select the century that makes the year closest to the current date. """ # fast exit for strictly conforming string m = strict_re.search(text) if m: g = m.groups() mon = months_lower.index(g[1].lower()) + 1 tt = (int(g[2]), mon, int(g[0]), int(g[3]), int(g[4]), float(g[5])) return my_timegm(tt) # No, we need some messy parsing... # clean up text = text.lstrip() text = wkday_re.sub("", text, 1) # Useless weekday # tz is time zone specifier string day, mon, yr, hr, min, sec, tz = [None] * 7 # loose regexp parse m = loose_http_re.search(text) if m is not None: day, mon, yr, hr, min, sec, tz = m.groups() else: return None # bad format return _str2time(day, mon, yr, hr, min, sec, tz) iso_re = re.compile( """^ (\d{4}) # year [-\/]? (\d\d?) # numerical month [-\/]? (\d\d?) # day (?: (?:\s+|[-:Tt]) # separator before clock (\d\d?):?(\d\d) # hour:min (?::?(\d\d(?:\.\d*)?))? # optional seconds (and fractional) )? # optional clock \s* ([-+]?\d\d?:?(:?\d\d)? |Z|z)? # timezone (Z is "zero meridian", i.e. GMT) \s*$""", re.X) def iso2time(text): """ As for http2time, but parses the ISO 8601 formats: 1994-02-03 14:15:29 -0100 -- ISO 8601 format 1994-02-03 14:15:29 -- zone is optional 1994-02-03 -- only date 1994-02-03T14:15:29 -- Use T as separator 19940203T141529Z -- ISO 8601 compact format 19940203 -- only date """ # clean up text = text.lstrip() # tz is time zone specifier string day, mon, yr, hr, min, sec, tz = [None] * 7 # loose regexp parse m = iso_re.search(text) if m is not None: # XXX there's an extra bit of the timezone I'm ignoring here: is # this the right thing to do? yr, mon, day, hr, min, sec, tz, _ = m.groups() else: return None # bad format return _str2time(day, mon, yr, hr, min, sec, tz)