python-3.x

问题 Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 2 years ago . Improve this question If I create a class as below, and check the type of the object, I get the following output. My question is what does __main__ mean here? class Student(object): pass >>>a = Student() >>>type(a) <class '__main__.Student'> There is another question, if I check the

问题 According to the documentation, a container that needs to be iterable should supply an __iter__() function to return an iterator. The iterator itself is required to follow the iterator protocol, meaning that it has to provide __iter__() that returns itself, and __next__() that provides the next item, or raises a StopIterator exception. Now I understand why both of those would be required in a container that does its own iteration, since you have to both provide an iterator and a next item:

问题 Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 2 years ago . Improve this question If I create a class as below, and check the type of the object, I get the following output. My question is what does __main__ mean here? class Student(object): pass >>>a = Student() >>>type(a) <class '__main__.Student'> There is another question, if I check the

问题 I have am trying to create the model class on which i want to add the extra field with ManytoMany field. On some google search I have identified its possible to through on implementing I am getting couple of errors which i am not able to identify whats the issue. Here is my model class: class CompQuantity(models.Model): comp_code = models.ForeignKey( 'core.SensorDevice', on_delete=models.CASCADE, null=True ) quantity = models.IntegerField() class PackageComponent(models.Model): pkg_code =

问题 I am trying this sample code that I found which is really really good. I am also trying to figure out the same thing to find an item and scroll to it, but this time I wanted to match the the string which has the EXACT WORD "cat" . Example matches: cat tom cat dog and cat super cat To make it very simple I am just trying to match an exact word in a string. Take this sample code as an example: import re s= "1 tom cat" s2 = "2 thundercat" if re.search(r'\bcat\b',s2): print("There is an EXACT

问题 I have set up a Django project with Celery and Redis. I am trying to send an OTP to a mobile number. The problem is whenever I try to execute the task by running sms_queue_processor.delay(phone, message) the celery worker doesn't receive the task. I tried the same executing from the shell but it doesn't receive at all. I tried to execute the statement from the shell at a rapid speed twice then the celery worker receives and I can able to receive the SMS. This is something weird and can't be

问题 I have created custom exception in python 3 and the over all code works just fine. But there is one thing I am not able to wrap my head around is that why do I need to send my message to the Exception class's __init__() and how does it convert the Custom exception into that string message when I try to print the exception since the code in the Exception or even the BaseException does not do much. Not quite able to understand why call the super().__init__() from custom exception? 回答1: This is

问题 I'm writing a script where a user has to provide input for each element of a large list. I'm trying to use tqdm to provide a progress bar for the user, but I can't find a good way to get input within the tqdm loop without breaking the output. I'm aware of tqdm.write() for writing to the terminal during a tqdm loop, but is there a way of getting input? For an example of what I'm trying to do, consider the code below: from tqdm import tqdm import sys from time import sleep def do_stuff(x):

问题 I'm in a AMD 64 bits Windows 10 computer in french with python 3.8.5 First I try to install kivy with the help of the official website (https://kivy.org/doc/stable/installation/installation-windows.html) but it failed while «Building wheel for kivy (setup.py)» The complet error has a length of 531 lines so I show only the more important part ERROR: Command errored out with exit status 3221225477: command: 'c:\users\%myusername%\appdata\local\programs\python\python38\python.exe' -u -c 'import

问题 I'm trying to schedule a operation every 30 minutes. But this code isn't working. def Advice(): print("30 minutes") @client.event async def on_ready(): schedule.every(30).minutes.do(Advice) Can you please help me? 回答1: This might be what you're looking for. Here's an example for you. class Heartbeat(commands.Cog): def __init__(self, bot): self.bot = bot self.heartbeat.start() def cog_unload(self): self.heartbeat.stop() @tasks.loop(seconds=45) async def heartbeat(self): if not self.bot.debug: