A-M baby

Task/Five-weekends/Python/five-weekends-1.py

@@ -0,0 +1,34 @@
+from datetime import timedelta, date
+
+DAY     = timedelta(days=1)
+START, STOP = date(1900, 1, 1), date(2101, 1, 1)
+WEEKEND = {6, 5, 4}     # Sunday is day 6
+FMT     = '%Y %m(%B)'
+
+def fiveweekendspermonth(start=START, stop=STOP):
+    'Compute months with five weekends between dates'
+
+    when = start
+    lastmonth = weekenddays = 0
+    fiveweekends = []
+    while when < stop:
+        year, mon, _mday, _h, _m, _s, wday, _yday, _isdst = when.timetuple()
+        if mon != lastmonth:
+            if weekenddays >= 15:
+                fiveweekends.append(when - DAY)
+            weekenddays = 0
+            lastmonth = mon
+        if wday in WEEKEND:
+            weekenddays += 1
+        when += DAY
+    return fiveweekends
+
+dates = fiveweekendspermonth()
+indent = '  '
+print('There are %s months of which the first and last five are:' % len(dates))
+print(indent +('\n'+indent).join(d.strftime(FMT) for d in dates[:5]))
+print(indent +'...')
+print(indent +('\n'+indent).join(d.strftime(FMT) for d in dates[-5:]))
+
+print('\nThere are %i years in the range that do not have months with five weekends'
+      % len(set(range(START.year, STOP.year)) - {d.year for d in dates}))

Task/Five-weekends/Python/five-weekends-2.py

@@ -0,0 +1,10 @@
+LONGMONTHS = (1, 3, 5, 7, 8, 10, 12) # Jan Mar May Jul Aug Oct Dec
+def fiveweekendspermonth2(start=START, stop=STOP):
+    return [date(yr, month, 31)
+            for yr in range(START.year, STOP.year)
+            for month in LONGMONTHS
+            if date(yr, month, 31).timetuple()[6] == 6 # Sunday
+            ]
+
+dates2 = fiveweekendspermonth2()
+assert dates2 == dates