デルタはクラス

Question

class timetravel(object): 
    """ 
    Fast forward in time with simulated CRON jobs (used for unit testing) 
    """ 
    delta = None 

def __init__(self, *args): 
    self.initial_now = datetime.now() 
    if isinstance(args[0], timedelta): 
     self.delta = delta 
    elif isinstance(args[0], datetime): 
     self.now = args[0] 
     if args[0] > self.initial_now: 
      self.delta = args[0] - self.initial_now 
     else: 
      self.delta = self.initial_now - args[0] 
    else: 
     print("Please provide a datetime or timedelta object as argument") 
    #self.now = self.initial_now 
    #self.freezer = freeze_time(self.now) 
    #self.freezer.start() 

def __enter__(self): 
    # Traveling in the past, we don't run cron jobs backward 
    if self.now < self.initial_now: 
     self.now = self.now - self.delta 
     self.freezer = freeze_time(self.now) 
     self.freezer.start() 
    # Traveling in the future, run cron jobs 
    else: 
     self.now = self.initial_now 
     self.freezer = freeze_time(self.now) 
     self.freezer.start() 
     hours = self.delta.total_seconds()/60/60 
     weekday = self.now.weekday() 
     month = self.now.month 
     year = self.now.year 
     for i in range(1, int(hours)+1): 
      call_command('cron', hourly=True, verbosity=0) 
      if weekday != self.now.weekday(): 
       weekday = self.now.weekday() 
       call_command('cron', daily=True) 
      if self.now.weekday() == 6 and weekday != self.now.weekday(): 
       call_command('cron', weekly=True) 
      if self.now.month != month: 
       month = self.now.month 
       call_command('cron', monthly=True) 
      if self.now.year != year: 
       year = self.now.year 
       call_command('cron', yearly=True) 
      self.freezer.stop() 
      self.now = self.now + timedelta(hours=1) 
      self.freezer = freeze_time(self.now) 
      self.freezer.start() 
    return self.now 

def __exit__(self, *args): 
    self.freezer.stop() 

で定義されていない、私は

Traceback (most recent call last): 
    File "...", line 42, in test_timetravel 
    with timetravel(datetime.timedelta(days=2)) as now: 
    File ".../utils/testing.py", line 23, in __init__ 
    self.delta = delta 
NameError: global name 'delta' is not defined 

を得る私が言うことはできません。

2この問題を解決するにはどうすればよいですか？実際には、私はプログラミングでは新しいです。だから、引数としてtimetravelに挿入する必要があるものの良い例は何でしょうか？

Answer 1

は、self.deltaのインスタンスからアクセスできるクラス属性です。この属性self.delta = 12を無効にすると、インスタンス属性になります。これはあなたの最初の質問は、SOであるため、レビューアとして

if isinstance(args[0], timedelta): 
    self.delta = delta