I have a python script. Lets say http://domain.com/hello.py, which only prints "Hello, World!".
Is it possible to precompile this Python file?
I get around 300 requests per second and the overhead of compiling is way to high. In Java the server can handle this easily but for calculations Python works much easier.
the problem is not that you need to "precompile" python, the problem is that you are trying to execute python scripts using normal cgi script stuff...
the real answer is to use a better web backend than simple cgi to run your python
I would suggest the following in order of appearance
1. nginx + gnunicorn
2. apache2 + mod-wsgi
3. something else
4. anything else
...
n-1. fcgi
n. cgi
I know this isnt really an answer and is entirely opinion based
Python code is compiled automatically the first time it is run, by the CPython (standard Python) interpreter. You can pre-compile it if you want to optimize the first request, but that usually isn't necessary. Aside from that, you'd need to convert your Python code into a Python C / cython Module. There are some tools to help you convert Python code into a Python Module if that's the route you want to go.
There's also a Python module called SciPy that's commonly used for Scientific Computing and Data Science applications, which provides a tool called Weave which allows you to inline C/C++ code into your Python code allowing certain performance-critical portions of the code to run using compiled C/C++ code.
via the python interface where your python source file is abc.py:
import py_compile
py_compile.compile('abc.py')
Related
I have been searching for an answer for quite some time and I cannot figure out a robust solution: I have a C# application (on Unity) which needs to call some python functions and libraries. In particular, the python code needs to read a very large tabular file from C# -the equivalent of a large pandas dataframe-, avoiding writing and reading through a file if possible, because given the size it would reduce the performance.
I am a total beginner to C#/Unity, and I have given a look at the following workarounds:
IronPython: it is not an option because the last stable version is for python 2.7. My requirements are python 3.6 and higher, moving towards 3.8.
PyInstaller: it creates .exe files and not .dll. Moreover, it is not clear to me how you could call the executable from C# and pass a dataframe/2D array without writing it on disk. I am also not sure whether it can be called passing an entire input file as argument, if you really want to communicate via files.
Communication via socket: I am a bit lost about it. If this is really feasible on both python and Unity sides, I am happy to see your tutorials -especially for Unity!
Unity Python script editor: it works fine in dev mode. However, the python scripts cannot be included in the build. This: https://forum.unity.com/threads/python-for-unity-editor-only.914843/#post-8330904 seems very suboptimal for a stable build.
Thank you for any hint!
I've written a 40k line program in python3. Now I need to use a module throughout my program that is called pytan which will impart a functionality addition. The problem is that pytan is written in python2.
So is it possible to switch the interpreter to python 2.7 inside one script that is called by another running in python 3?
What's the best way to handle this situation.
You cannot "switch the interpreter to python 2.7". You're either using one or the other. Your choices are effectively:
Come up with an alternative that doesn't require the pytan module.
Modify the pytan module so that it runs under Python 3.
Modify your code so that it runs under Python 2.
Isolate the code that requires pytan such that you can run it as a subprocess under the python 2 interpreter. There are a number of problems with this solution:
It requires people to have two versions of Python installed.
It will complicate things like syntax highlighting in your editor.
It will complicate testing.
It may require some form of IPC (pipes, sockets, files, etc...) between your main code and your python 2 subprocess (this isn't terrible, but it's a chunk of additional complexity that wouldn't be necessary if you could make one of the other options work).
If I have a script, or in this case just a function or two, written in Jython -- is there a way to interact with that code from my Python3 project?
No, not until Jython catches up with CPython enough for your whole Python 3 project to run in Jython. You can't run part of a Python application with one interpreter and the rest with another. You might be able to juggle multiple processes using remote procedure calls using pickle, but it'll be complex and brittle, not to mention slow (has to copy all data involved). If it's pure Python, just port those two functions to Python 3 (likely easy), or port your project to Python 2.5 (probably much harder). If it uses Jython's JVM interop, there are alternatives working with CPython, though possibly less mature. Depending on what you need Java for, there might be a pure Python alternative.
I have a Delphi Win32 program. I want to "expose" somehow app structures and procedures via Python module. E.g. module my_api must expose public items for my app structures/methods. This module must "sit" in memory only.
Then I want, in the same app, to call Python scripts (using Python dll) which can import my_api and call my app methods.
How to do it.
You're asking for two things here, which often go together.
First, you want to extend the Python interpreter, adding types and functions and so forth that Python code can use.
Second, you want to embed the Python interpreter in your app, so it can run Python scripts (which can use your extension modules).
Assuming you want to use CPython (the usual Python interpreter), the tutorial Extending and Embedding the Python Interpreter is part of the docs.
You may want to look at other options that help make the extending side easier—for example, you can use Cython to write the bridge code in a near-Python language instead of C, or Boost.Python to write it in nice C++ that takes care of most of the boilerplate for you, or SWIG to try to generate it automatically, or ctypes to avoid writing a bridge in the first place. But it's worth learning the underlying mechanism first.
You may have heard of Python 4 Delphi by now, and if you haven't you can look it up here. https://code.google.com/p/python4delphi/. There are quite a few tutorials on the internet e,g http://www.atug.com/andypatterns/pythonDelphiTalk.htm
Although I found many answers and discussions about this question, I am unable to find a solution particular to my situation. Here it is:
I have a main program written in FORTRAN.
I have been given a set of python scripts that are very useful.
My goal is to access these python scripts from my main FORTRAN program. Currently, I simply call the scripts from FORTRAN as such:
CALL SYSTEM ('python pyexample.py')
Data is read from .dat files and written to .dat files. This is how the python scripts and the main FORTRAN program communicate to each other.
I am currently running my code on my local machine. I have python installed with numpy, scipy, etc.
My problem:
The code needs to run on a remote server. For strictly FORTRAN code, I compile the code locally and send the executable to the server where it waits in a queue. However, the server does not have python installed. The server is being used as a number crunching station between universities and industry. Installing python along with the necessary modules on the server is not an option. This means that my “CALL SYSTEM ('python pyexample.py')” strategy no longer works.
Solution?:
I found some information on a couple of things in thread Is it feasible to compile Python to machine code?
Shedskin, Psyco, Cython, Pypy, Cpython API
These “modules”(? Not sure if that's what to call them) seem to compile python script to C code or C++. Apparently not all python features can be translated to C. As well, some of these appear to be experimental. Is it possible to compile my python scripts with my FORTRAN code? There exists f2py which converts FORTRAN code to python, but it doesn't work the other way around.
Any help would be greatly appreciated. Thank you for your time.
Vincent
PS: I'm using python 2.6 on Ubuntu
One way or another, you'll need to get the Python runtime on your server, otherwise it won't be possible to execute Python bytecode. Ignacio is on the right track with suggesting invoking libpython directly, but due to Fortran's parameter-passing conventions, it will be a lot easier for you to write a C wrapper to handle the interface between Fortran and the CPython embedding API.
Unfortunately, you're doing this the hard way -- it's a lot easier to write a Python program that can call Fortran subroutines than the other way around.
You don't want any of those. What you should do is use FORTRAN's FFI to talk with libpython and frob its API.