Optional.py

class Optional:

  def __init__(self, inner):
    self.inner = inner
    self.err = None

  def map(self, func):

    if self.err is not None:
      return self

    try:
      self.inner = func(self.inner)
    except Exception as e:
      self.err = e
      self.inner = None

    return self

  def optional_result(self):
    if self.err:
      raise self.err

    return self.inner

  def __getattr__(self, item):

    def wrapper_func(*args, **kwargs):
      self.inner = getattr(self.inner, item)(*args, **kwargs)
      return self

    return wrapper_func




  target_hours_so_far = (
    Optional(sheets.values())
      .get(spreadsheetId=TIMESHEET_RAW_ID, range="R3:S")
      .execute()
      .get("values", [])
      .map(lambda x: filter(lambda i: i[0] == localized_year, x))
      .map(lambda x: next(x))
      .map(lambda x: x[1])
      .map(lambda x: dt.timedelta(hours=int(float(x))))
      .optional_result()
  )