python-3.4

I have just moved on to python3 as a result of its concurrent futures module. I was wondering if I could get it to detect errors. I want to use concurrent futures to parallel program, if there are more efficent modules please let me know. I do not like multiprocessing as it is too complicated and not much documentation is out. It would be great however if someone could write a Hello World without classes only functions using multiprocessing to parallel compute so that it is easy to understand. Here is a simple script: from concurrent.futures import ThreadPoolExecutor def pri(): print("Hello

I suppose this is a general question so sorry if not posted in the right place. Say for instance, I have a function a which imports os . If I was to call this function from another file multiple times I am assuming that the import would be done multiple times as well? Is there a way to only import the module if its not already present? Basically, I have a class which calls multiple functions imported from various files, instead of importing the whole file I thought it would be easier to import just the function but now I am wondering if I am going to give myself headaches in the long run with

For this directory hierarchy: . ├── hello │ ├── __init__.py │ └── world │ └── __init__.py └── test.py And the Python source files: test.py: if __name__ == '__main__': import hello hello/__init__.py: import world hello/world/__init__.py: print("yes you win") Running test.py with Python 3.4 throws ImportError saying that module world is not found, but with Python 2.7 everything is fine. I know that sys.path is referenced when searching for the imported modules, so adding the directory hello to sys.path eliminates the error. But in Python 2.7, before importing world , the directory hello is not

I want to parse strings into python enums. Normally one would implement a parse method to do so. A few days ago I spotted the __new__ method which is capable of returning different instances based on a given parameter. Here my code, which will not work: import enum class Types(enum.Enum): Unknown = 0 Source = 1 NetList = 2 def __new__(cls, value): if (value == "src"): return Types.Source # elif (value == "nl"): return Types.NetList # else: raise Exception() def __str__(self): if (self == Types.Unknown): return "??" elif (self == Types.Source): return "src" elif (self == Types.NetList): return

I am using Ubuntu 12.04 and want to use python 3.4 side by side with python 2.7. The installation of python 3.4 worked properly. However, I cannot install the numpy package for python 3 (and as a consequence I can't install scipy, pandas etc.). Using sudo pip3 install numpy spits out the following error: File "numpy/core/setup.py", line 289, in check_types "Cannot compile 'Python.h'. Perhaps you need to "\ SystemError: Cannot compile 'Python.h'. Perhaps you need to install python-dev|python-devel. Btw, I already have python-dev installed. Moreover, installing numpy via sudo apt-get install

I have an event loop that runs some co-routines as part of a command line tool. The user may interrupt the tool with the usual Ctrl + C , at which point I want to clean up properly after the interrupted event loop. Here's what I tried. 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 = asyncio.get_event_loop() # Side note: Apparently, async() will be deprecated in 3.4.4. # See: https://docs.python.org/3.4/library/asyncio-task.html#asyncio.async tasks = [ asyncio