python - locale in dateutil / parser

dateutil.parser doesn't use locale. You'll need to subclass dateutil.parser.parserinfo and construct a German equivalent:.

from dateutil import parser

class GermanParserInfo(parser.parserinfo):
    WEEKDAYS = [("Mo.", "Montag"),
                ("Di.", "Dienstag"),
                ("Mi.", "Mittwoch"),
                ("Do.", "Donnerstag"),
                ("Fr.", "Freitag"),
                ("Sa.", "Samstag"),
                ("So.", "Sonntag")]

s = 'Montag, 11. April 2016 19:35:57'
note_date = parser.parse(s, parserinfo=GermanParserInfo())

You'd need to extend this to also work for other values, such as month names.