meetup exercise

python/meetup/meetup.py

@@ -0,0 +1,39 @@
+import datetime, pprint, calendar
+
+ordinal_meaning = {
+    'first' : 0,
+    'second' : 1,
+    'third' : 2,
+    'fourth' : 3,
+    'fifth' : 4,
+    'last' : -1
+}
+
+weekday_meaning = {
+    'monday' : 0,
+    'tuesday' : 1,
+    'wednesday' : 2,
+    'thursday' : 3,
+    'friday' : 4,
+    'saturday' : 5,
+    'sunday' : 6
+}
+
+class MeetupDayException(Exception):
+    def __init__(self, expression, message):
+        self.expression, self.message = expression, message
+
+def meetup(year, month, week, day_of_week):
+    # Get all days in a month
+    days = [datetime.date(year, month, day) for day in range(1, calendar.monthrange(year, month)[1] + 1)]
+    # Filter to the day of week being targeted
+    days = [date for date in days if date.weekday() == weekday_meaning[day_of_week.lower()]]
+    if week in ordinal_meaning.keys():
+        return days[ordinal_meaning[week]]
+    elif week == 'teenth':
+        return [date for date in days if date.day <= 19 and date.day >= 13][0]
+    else:
+        try:
+            return days[int(week[0]) - 1]
+        except IndexError as err:
+            raise MeetupDayException(err, "Invalid date parameter \'{}\'".format(week))