MySQLdb does not support Python 3 but it is not the only MySQL driver for Python. mysqlclient is essentially just a fork of MySQLdb with Python 3 support merged in (and a few other improvements). PyMySQL is a pure python MySQL driver, which means it is slower, but it does not require a compiled C … Read more
Update: As of Python 3.8, functools.singledispatchmethod allows single dispatch on methods, classmethods, abstractmethods, and staticmethods. For older Python versions, see the rest of this answer. Looking at the source for singledispatch, we can see that the decorator returns a function wrapper(), which selects a function to call from those registered based on the type of … Read more
The problem comes from closing the loop immediately after cancelling the tasks. As the cancel() docs state “This arranges for a CancelledError to be thrown into the wrapped coroutine on the next cycle through the event loop.” Take this snippet of code: import asyncio import signal async def pending_doom(): await asyncio.sleep(2) print(“>> Cancelling tasks now”) … Read more
As of python-3.5, there is pathlib.Path.home(), which improves the situation somewhat. The result on Windows is >>>pathlib.Path.home() WindowsPath(‘C:/Users/username’) and on Linux >>>pathlib.Path.home() PosixPath(‘/home/username’)
1. When and where to use enums? When you have a variable that takes one of a limited set of possible values. For example, the days of the week: class Weekday(Enum): MONDAY = 1 TUESDAY = 2 WEDNESDAY = 3 THURSDAY = 4 FRIDAY = 5 SATURDAY = 6 SUNDAY = 7 2. Why do … Read more
When you CTRL+C, the event loop gets stopped, so your calls to t.cancel() don’t actually take effect. For the tasks to be cancelled, you need to start the loop back up again. Here’s how you can handle it: import asyncio @asyncio.coroutine def shleepy_time(seconds): print(“Shleeping for {s} seconds…”.format(s=seconds)) yield from asyncio.sleep(seconds) if __name__ == ‘__main__’: loop … Read more
The error is pretty clear. The file hello.py is not an executable file. You need to specify the executable: subprocess.call([‘python.exe’, ‘hello.py’, ‘htmlfilename.htm’]) You’ll need python.exe to be visible on the search path, or you could pass the full path to the executable file that is running the calling script: import sys subprocess.call([sys.executable, ‘hello.py’, ‘htmlfilename.htm’])
The coroutines work as is. Just use the returned value from loop.run_until_complete() and call asyncio.gather() to collect multiple results: #!/usr/bin/env python3 import asyncio @asyncio.coroutine def func_normal(): print(‘A’) yield from asyncio.sleep(5) print(‘B’) return ‘saad’ @asyncio.coroutine def func_infinite(): for i in range(10): print(“–%d” % i) return ‘saad2’ loop = asyncio.get_event_loop() tasks = func_normal(), func_infinite() a, b = … Read more
If you don’t use conda, just use : pip install openpyxl If you use conda, I’d recommend : conda install -c anaconda openpyxl instead of simply conda install openpyxl Because there are issues right now with conda updating (see GitHub Issue #8842) ; this is being fixed and it should work again after the next … Read more
The easiest way I’ve found to install pip3 (for python3.x packages) on CentOS 7 is: $ sudo yum install python34-setuptools $ sudo easy_install-3.4 pip You’ll need to have the EPEL repository enabled before hand, of course. You should now be able to run commands like the following to install packages for python3.x: $ pip3 install … Read more