Collapse Weekdays

collapse_weekdays.py

days_default = {'월':0, '화':1, '수':2, '목':3, '금':4, '토':5, '일':6}

# input: 0, 1, 2, 4, 6
# output: 0~2, 4, 6

reverse= dict((v, k) for k, v in days_default.items())
def collapse_weekdays(days):
    days = list(map(lambda k: days_default.get(k), days))
    
    shift = lambda n, k: (n + 1 < k and days[n + 1] - days[n] == 1) and shift(n + 1, k) or n
    
    def collapse(i, k, acc):
      if i < k:
        day = days[i]
        i = shift(i, k)
        acc.append((day, days[i]) if days[i] != day else day)
        return collapse(i + 1, k, acc)
      else:
        return acc
    
    return list(map(
      lambda v:
        (isinstance(v, tuple) and (reverse.get(v[0]) + '~' + reverse.get(v[1])))
        or reverse.get(v)
        , collapse(0, len(days), [])
      ) # end of map
    ) # end of list

print(collapse_weekdays(['월','화','수','금','일'])) #['월~수', '금', '일']
print(collapse_weekdays(['월','화','수','금','토','일'])) #['월~수', '금~일']