modules: Added a TVRage.com parser along with a rfc3339 parser and formatter.

1 files changed, 296 insertions, 0 deletions

diff --git a/rfc3339.py b/rfc3339.py
new file mode 100644
index 0000000..95d7249
--- /dev/null
+++ b/rfc3339.py
@@ -0,0 +1,296 @@
+# rfc3339.py -- Implementation of the majority of RFC 3339 for python.
+# Copyright (c) 2008, 2009, 2010 LShift Ltd. <query@lshift.net>
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+
+"""
+Implementation of the majority of http://www.ietf.org/rfc/rfc3339.txt.
+
+Use datetime.datetime.isoformat() as an inverse of the various parsing
+routines in this module.
+
+Limitations, with respect to RFC 3339:
+
+ - Section 4.3, "Unknown Local Offset Convention", is not implemented.
+
+ - Section 5.6, "Internet Date/Time Format", is the ONLY supported format
+   implemented by the various parsers in this module. (Section 5.6 is
+   reproduced in its entirety below.)
+
+ - Section 5.7, "Restrictions", is left to the datetime.datetime constructor
+   to implement, with the exception of limits on timezone
+   minutes-east-of-UTC magnitude. In particular, leap seconds are not
+   addressed by this module. (And it appears that they are not supported
+   by datetime, either.)
+
+Potential Improvements:
+
+ - Support for leap seconds. (There's a table of them in RFC 3339 itself,
+   and http://tf.nist.gov/pubs/bulletin/leapsecond.htm updates monthly.)
+
+Here's an excerpt from RFC 3339 itself:
+
+5.6. Internet Date/Time Format
+
+   The following profile of ISO 8601 [ISO8601] dates SHOULD be used in
+   new protocols on the Internet.  This is specified using the syntax
+   description notation defined in [ABNF].
+
+   date-fullyear   = 4DIGIT
+   date-month      = 2DIGIT  ; 01-12
+   date-mday       = 2DIGIT  ; 01-28, 01-29, 01-30, 01-31 based on
+                             ; month/year
+   time-hour       = 2DIGIT  ; 00-23
+   time-minute     = 2DIGIT  ; 00-59
+   time-second     = 2DIGIT  ; 00-58, 00-59, 00-60 based on leap second
+                             ; rules
+   time-secfrac    = "." 1*DIGIT
+   time-numoffset  = ("+" / "-") time-hour ":" time-minute
+   time-offset     = "Z" / time-numoffset
+
+   partial-time    = time-hour ":" time-minute ":" time-second
+                     [time-secfrac]
+   full-date       = date-fullyear "-" date-month "-" date-mday
+   full-time       = partial-time time-offset
+
+   date-time       = full-date "T" full-time
+
+      NOTE: Per [ABNF] and ISO8601, the "T" and "Z" characters in this
+      syntax may alternatively be lower case "t" or "z" respectively.
+
+      This date/time format may be used in some environments or contexts
+      that distinguish between the upper- and lower-case letters 'A'-'Z'
+      and 'a'-'z' (e.g. XML).  Specifications that use this format in
+      such environments MAY further limit the date/time syntax so that
+      the letters 'T' and 'Z' used in the date/time syntax must always
+      be upper case.  Applications that generate this format SHOULD use
+      upper case letters.
+
+      NOTE: ISO 8601 defines date and time separated by "T".
+      Applications using this syntax may choose, for the sake of
+      readability, to specify a full-date and full-time separated by
+      (say) a space character.
+"""
+
+import datetime, time, calendar
+import re
+
+__all__ = ["tzinfo", "UTC_TZ", "parse_date", "parse_datetime", "now", "utcfromtimestamp", "utctotimestamp", "datetimetostr", "timestamptostr", "strtotimestamp"]
+
+ZERO = datetime.timedelta(0)
+
+class tzinfo(datetime.tzinfo):
+    """
+    Implementation of a fixed-offset tzinfo.
+    """
+    def __init__(self, minutesEast, name):
+        """
+        minutesEast -> number of minutes east of UTC that this tzinfo represents.
+        name -> symbolic (but uninterpreted) name of this tzinfo.
+        """
+        self.minutesEast = minutesEast
+        self.offset = datetime.timedelta(minutes = minutesEast)
+        self.name = name
+
+    def utcoffset(self, dt):
+        """Returns minutesEast from the constructor, as a datetime.timedelta."""
+        return self.offset
+
+    def dst(self, dt):
+        """This is a fixed offset tzinfo, so always returns a zero timedelta."""
+        return ZERO
+
+    def tzname(self, dt):
+        """Returns the name from the constructor."""
+        return self.name
+
+    def __repr__(self):
+        """If minutesEast==0, prints specially as rfc3339.UTC_TZ."""
+        if self.minutesEast == 0:
+            return "rfc3339.UTC_TZ"
+        else:
+            return "rfc3339.tzinfo(%s,%s)" % (self.minutesEast, repr(self.name))
+
+UTC_TZ = tzinfo(0, 'Z')
+
+date_re_str = r'(\d\d\d\d)-(\d\d)-(\d\d)'
+time_re_str = r'(\d\d):(\d\d):(\d\d)(\.(\d+))?([zZ]|(([-+])(\d\d):(\d\d)))'
+
+def make_re(*parts):
+    return re.compile(r'^\s*' + ''.join(parts) + r'\s*$')
+
+date_re = make_re(date_re_str)
+datetime_re = make_re(date_re_str, r'[ tT]', time_re_str)
+
+def parse_date(s):
+    """
+    Given a string matching the 'full-date' production above, returns
+    a datetime.date instance. Any deviation from the allowed format
+    will produce a raised ValueError.
+
+    >>> parse_date("2008-08-24")
+    datetime.date(2008, 8, 24)
+    >>> parse_date("   2008-08-24       ")
+    datetime.date(2008, 8, 24)
+    >>> parse_date("2008-08-00")
+    Traceback (most recent call last):
+      File "<stdin>", line 1, in <module>
+      File "rfc3339.py", line 134, in parse_date
+        return datetime.date(int(y), int(m), int(d))
+    ValueError: day is out of range for month
+    >>> parse_date("2008-06-31")
+    Traceback (most recent call last):
+      File "<stdin>", line 1, in <module>
+      File "rfc3339.py", line 134, in parse_date
+        return datetime.date(int(y), int(m), int(d))
+    ValueError: day is out of range for month
+    >>> parse_date("2008-13-01")
+    Traceback (most recent call last):
+      File "<stdin>", line 1, in <module>
+      File "rfc3339.py", line 134, in parse_date
+        return datetime.date(int(y), int(m), int(d))
+    ValueError: month must be in 1..12
+    >>> parse_date("22008-01-01")
+    Traceback (most recent call last):
+      File "<stdin>", line 1, in <module>
+      File "rfc3339.py", line 136, in parse_date
+        raise ValueError('Invalid RFC 3339 date string', s)
+    ValueError: ('Invalid RFC 3339 date string', '22008-01-01')
+    >>> parse_date("2008-08-24").isoformat()
+    '2008-08-24'
+    """
+    m = date_re.match(s)
+    if m:
+        (y, m, d) = m.groups()
+        return datetime.date(int(y), int(m), int(d))
+    else:
+        raise ValueError('Invalid RFC 3339 date string', s)
+
+def parse_datetime(s):
+    """
+    Given a string matching the 'date-time' production above, returns
+    a datetime.datetime instance. Any deviation from the allowed
+    format will produce a raised ValueError.
+
+    >>> parse_datetime("2008-08-24T00:00:00Z")
+    datetime.datetime(2008, 8, 24, 0, 0, tzinfo=rfc3339.UTC_TZ)
+    >>> parse_datetime("   2008-08-24T00:00:00Z ")
+    datetime.datetime(2008, 8, 24, 0, 0, tzinfo=rfc3339.UTC_TZ)
+    >>> parse_datetime("2008-08-24T00:00:00")
+    Traceback (most recent call last):
+      File "<stdin>", line 1, in <module>
+      File "rfc3339.py", line 208, in parse_datetime
+        raise ValueError('Invalid RFC 3339 datetime string', s)
+    ValueError: ('Invalid RFC 3339 datetime string', '2008-08-24T00:00:00')
+    >>> parse_datetime("2008-08-24T00:00:00+00:00")
+    datetime.datetime(2008, 8, 24, 0, 0, tzinfo=rfc3339.UTC_TZ)
+    >>> parse_datetime("2008-08-24T00:00:00+01:00")
+    datetime.datetime(2008, 8, 24, 0, 0, tzinfo=rfc3339.tzinfo(60,'+01:00'))
+    >>> parse_datetime("2008-08-24T00:00:00-01:00")
+    datetime.datetime(2008, 8, 24, 0, 0, tzinfo=rfc3339.tzinfo(-60,'-01:00'))
+    >>> parse_datetime("2008-08-24T24:00:00Z")
+    Traceback (most recent call last):
+      File "<stdin>", line 1, in <module>
+      File "rfc3339.py", line 206, in parse_datetime
+        tz)
+    ValueError: hour must be in 0..23
+    >>> midnightUTC = parse_datetime("2008-08-24T00:00:00Z")
+    >>> oneamBST = parse_datetime("2008-08-24T01:00:00+01:00")
+    >>> midnightUTC == oneamBST
+    True
+    >>> elevenpmUTC = parse_datetime("2008-08-23T23:00:00Z")
+    >>> midnightBST = parse_datetime("2008-08-24T00:00:00+01:00")
+    >>> midnightBST == elevenpmUTC
+    True
+    >>> elevenpmUTC.isoformat()
+    '2008-08-23T23:00:00+00:00'
+    >>> oneamBST.isoformat()
+    '2008-08-24T01:00:00+01:00'
+    >>> parse_datetime("2008-08-24T00:00:00.123Z").isoformat()
+    '2008-08-24T00:00:00.123000+00:00'
+    """
+    m = datetime_re.match(s)
+    if m:
+        (y, m, d, hour, min, sec, ignore1, frac_sec, wholetz, ignore2, tzsign, tzhour, tzmin) = \
+            m.groups()
+
+        if frac_sec:
+            frac_sec = float("0." + frac_sec)
+        else:
+            frac_sec = 0
+        microsec = int((frac_sec * 1000000) + 0.5)
+
+        if wholetz == 'z' or wholetz == 'Z':
+            tz = UTC_TZ
+        else:
+            tzhour = int(tzhour)
+            tzmin = int(tzmin)
+            offset = tzhour * 60 + tzmin
+            if offset == 0:
+                tz = UTC_TZ
+            else:
+                if tzhour > 24 or tzmin > 60 or offset > 1439: ## see tzinfo docs for the 1439 part
+                    raise ValueError('Invalid timezone offset', s, wholetz)
+
+                if tzsign == '-':
+                    offset = -offset
+                tz = tzinfo(offset, wholetz)
+
+        return datetime.datetime(int(y), int(m), int(d),
+                                 int(hour), int(min), int(sec), microsec,
+                                 tz)
+    else:
+        raise ValueError('Invalid RFC 3339 datetime string', s)
+
+def now():
+    """Return a timezone-aware datetime.datetime object in
+    rfc3339.UTC_TZ timezone, representing the current moment
+    (time.time()). Useful as a replacement for the (timezone-unaware)
+    datetime.datetime.now() method."""
+    return utcfromtimestamp(time.time())
+
+def utcfromtimestamp(unix_epoch_timestamp):
+    """Interprets its argument as a count of seconds elapsed since the
+    Unix epoch, and returns a datetime.datetime in rfc3339.UTC_TZ
+    timezone."""
+    (y, m, d, hour, min, sec) = time.gmtime(unix_epoch_timestamp)[:6]
+    return datetime.datetime(y, m, d, hour, min, sec, 0, UTC_TZ)
+
+def utctotimestamp(dt):
+    """Returns a count of the elapsed seconds between the Unix epoch
+    and the passed-in datetime.datetime object."""
+    return calendar.timegm(dt.utctimetuple())
+
+def datetimetostr(dt):
+    """Return a RFC3339 date-time string corresponding to the given
+    datetime object."""
+    if dt.utcoffset() is not None:
+        return dt.isoformat()
+    else:
+        return "%sZ" % dt.isoformat()
+
+def timestamptostr(ts):
+    """Return a RFC3339 date-time string corresponding to the given
+    Unix-epoch timestamp."""
+    return datetimetostr(utcfromtimestamp(ts))
+
+def strtotimestamp(s):
+    """Return the Unix-epoch timestamp corresponding to the given RFC3339
+    date-time string."""
+    return utctotimestamp(parse_datetime(s))