programming - How to use Mathematica functions in Python programs?

I'd like to know how can I call Mathematica functions from Python.

I appreciate a example, for example, using the Mathematica function Prime.

I had search about MathLink but how to use it in Python is a little obscure to me.

I tried to use a Mathematica-Python library called pyml but I hadn't no sucess, maybe because this lib looks very old (in tutorial says Mathematica 2 or 3).

So, someone knows a good way to write python programs who uses Mathematica functions and can give me an example?

Old Edit:

Maybe this edit can help someone who wants to use mathlinks directly.

To another solution, please see the answer accepted.

Using the Wolfram/Mathematica/8.0/SystemFiles/Links/Python I could had sucess in compiling the module changing some things in setup.py.

My architechture is x86-64.

1-Change the mathematicaversion to 8.0.

2-Changing the lib name ML32i3 to ML64i3.

3-Copying the file Wolfram/Mathematica/8.0/SystemFiles/Libraries/Linux-x86-64/libML64i3.so to the path pointed in setup.py library_dirs = ["/usr/local/Wolfram/Mathematica/" + mathematicaversion + "/SystemFiles/Links/MathLink/DeveloperKit/Linux/CompilerAdditions"].

5-Compiling the source with sudo python setup.py build.

6-Installing the lib with sudo python setup.py install

4-Editing the file /etc/ld.so.conf and putting the line include /usr/local/lib.

5-Creating a directory in /usr/local/lib/python2.6/dist-packages/mathlink with the lib libML64i3.so.

6-Running sudo ldconfig

I had tested the scripts guifrontend.py with python guifrontend.py -linkname "math -mathlink" -linkmode launch and textfrontend.py with python textfrontend.py -linkname "math -mathlink" -linkmode launch and worked fine.

Looks like I almost. But the script

>>> from mathlink import *
>>> import exceptions,sys, re, os
>>> from types import ListType
>>> mathematicaversion = "8.0"
>>> os.environ["PATH"] = "/usr/local/Wolfram/Mathematica/" + mathematicaversion + ":/usr/local/bin:/usr/bin:/bin"
>>> e = env()
>>> sys.argv=['textfrontend.py', '-linkname', 'math -mathlink', '-linkmode', 'launch']
>>> kernel = e.openargv(sys.argv)
>>> kernel.connect()

>>> kernel.ready()
0
>>> kernel.putfunction("Prime",1)
>>> kernel.putinteger(10)
>>> kernel.flush()
>>> kernel.ready()
0
>>> kernel.nextpacket()
8
>>> packetdescriptiondictionary[3]

'ReturnPacket'
>>> kernel.getinteger()
Traceback (most recent call last):
  File "", line 1, in 
mathlink.error: MLGet out of sequence.

breaks in the last command and I don't know why. How can I fix this?

Answer

This solution can work with several programming languages. Check this GitHub repository of mine.

See this link.

I have found a solution. Works fine to me.

Steps:

1-Create a script named runMath with the content:

#!/usr/bin/env wolframscript
# for certain older versions of Mathematica replace 'wolframscript' by
# 'MathematicaScript -script' in the shebang line

value=ToExpression[$ScriptCommandLine[[2]]];

(*The next line prints the script name.*)

(*Print[$ScriptCommandLine[[1]]];*)

Print[value];

2-I gave execution privilege to the file.

sudo chmod +x runMath

3-Moved the file to the execution path

sudo mv runMath /usr/local/bin/

4-Created a new script called run with the content:

#!/usr/bin/python
from subprocess import *
from sys import *

command='/usr/local/bin/runMath'
parameter=argv[1]

call([command,parameter])

5-Moved to the execution path

sudo mv run /usr/local/bin

6-Finally, tested it:

$run Prime[100]
541

$run 'Sum[2x-1,{x,1,k}]'
k^2


$run Integrate[Log[x],x]
-x + x*Log[x]

$run 'Zeta[2]'
Pi^2/6

You can use with ou without '. The ' are needed to command with spaces.

$run 'f[n_] := f[n] = f[n - 1] + f[n - 2]; f[1] = f[2] = 1; Table[f[n],{n,5}]'
{1, 1, 2, 3, 5}

Happy!