Initial import

ebook_converter/utils/iso8601.py

@@ -0,0 +1,65 @@
+#!/usr/bin/env python2
+# vim:fileencoding=utf-8
+# License: GPLv3 Copyright: 2016, Kovid Goyal <kovid at kovidgoyal.net>
+
+from __future__ import absolute_import, division, print_function, unicode_literals
+from datetime import datetime
+
+from dateutil.tz import tzlocal, tzutc, tzoffset
+
+from calibre.constants import plugins
+speedup, err = plugins['speedup']
+if not speedup:
+    raise RuntimeError(err)
+
+
+class SafeLocalTimeZone(tzlocal):
+
+    def _isdst(self, dt):
+        # This method in tzlocal raises ValueError if dt is out of range (in
+        # older versions of dateutil)
+        # In such cases, just assume that dt is not DST.
+        try:
+            return super(SafeLocalTimeZone, self)._isdst(dt)
+        except Exception:
+            pass
+        return False
+
+    def _naive_is_dst(self, dt):
+        # This method in tzlocal raises ValueError if dt is out of range (in
+        # newer versions of dateutil)
+        # In such cases, just assume that dt is not DST.
+        try:
+            return super(SafeLocalTimeZone, self)._naive_is_dst(dt)
+        except Exception:
+            pass
+        return False
+
+
+utc_tz = tzutc()
+local_tz = SafeLocalTimeZone()
+del tzutc, tzlocal
+UNDEFINED_DATE = datetime(101,1,1, tzinfo=utc_tz)
+
+
+def parse_iso8601(date_string, assume_utc=False, as_utc=True):
+    if not date_string:
+        return UNDEFINED_DATE
+    dt, aware, tzseconds = speedup.parse_iso8601(date_string)
+    tz = utc_tz if assume_utc else local_tz
+    if aware:  # timezone was specified
+        if tzseconds == 0:
+            tz = utc_tz
+        else:
+            sign = '-' if tzseconds < 0 else '+'
+            description = "%s%02d:%02d" % (sign, abs(tzseconds) // 3600, (abs(tzseconds) % 3600) // 60)
+            tz = tzoffset(description, tzseconds)
+    dt = dt.replace(tzinfo=tz)
+    if as_utc and tz is utc_tz:
+        return dt
+    return dt.astimezone(utc_tz if as_utc else local_tz)
+
+
+if __name__ == '__main__':
+    import sys
+    print(parse_iso8601(sys.argv[-1]))