Run Python with package NumPy in Mathematica

Question

For example, if I have a Python script called simple.py that contains code as simple as

a=1
print(a)

then

RunProcess[{"python", "E:\\w\\simple.py"}]

is OK and gives

<|"ExitCode" -> 0, "StandardOutput" -> "1

  ", "StandardError" -> ""|>

However, if I edit simple.py as

import numpy as np
a=np.array([1,2])
print(a)

then

RunProcess[{"python", "E:\\w\\simple.py"}]

gives

<|"ExitCode" -> 1, "StandardOutput" -> "",
 "StandardError" -> "Traceback (most recent call last):

    File \"E:\\w\\WORK\\python\\learning\\simple.py\", line 1, in \
<module>

      import numpy as np

    File \"D:\\IntelPython35\\lib\\site-packages\\numpy\\__init__.py\"\
, line 158, in <module>

      from . import add_newdocs

    File \"D:\\IntelPython35\\lib\\site-packages\\numpy\\add_newdocs.\
py\", line 13, in <module>

      from numpy.lib import add_newdoc

    File \"D:\\IntelPython35\\lib\\site-packages\\numpy\\lib\\__init__\
.py\", line 8, in <module>

      from .type_check import *

    File \"D:\\IntelPython35\\lib\\site-packages\\numpy\\lib\\type_\
check.py\", line 11, in <module>

      import numpy.core.numeric as _nx

    File \"D:\\IntelPython35\\lib\\site-packages\\numpy\\core\\__init_\
_.py\", line 21, in <module>

      from . import umath

  ImportError: DLL load failed: ÕÒ\.b2»\[Micro]½Ö¸\[Paragraph]¨\
\[Micro]Ä\.b3ÌÐò¡£

  "|>

What is wrong? How can I make NumPy work with RunProcess?

---

Update

I've tried on a Linux computer. The same Python script works. So is it a problem of why RunProcess doesn't import packages correctly on Windows?

---

Update

A workaround.

I uninstalled Intel Python and install Anaconda.

Now it is working. Maybe Intel Python misses something in the PATH.

Answer 1

Starting in version 11.2 you may use ExternalEvaluate to run Python from Mathematica. See the Configure Python for ExternalEvaluate tutorial for setup.

session = StartExternalSession[<|"System" -> "Python", "ReturnType" -> "Expression"|>]

Then

res = ExternalEvaluate[session, 
  "import numpy as np; a=np.array([1,2]); a.tolist()"]

{1, 2}

End the session with the following.

DeleteObject@session

Hope this helps.

Answer 2

I don't know how to resolve your issue, but here are my two cents.

I think it's likely a process environment issue as this works for me on Mac with Mathematica 11.1:

RunProcess[{"python3.4", "-i"},
 "StandardOutput",
 "import numpy as np; a=np.array([1,2]); print(a)",
 ProcessEnvironment ->
  <|
   "PATH" -> "/usr/local/bin:" <> Environment["PATH"]
   |>
 ]

"[1 2]
"

The different ProcessEnvironment is something I always need to run python, since I never bother to use SetEnvironment

Answer 3

I installed IntelPython3 on Windows 7 and this worked (with Mathematica 10.1) for me:

SetDirectory["\\Users\\gauss\\Documents\\Python Scripts"]
RunProcess[{"C:\\IntelPython3\\python.exe", "simple.py"}]

It worked without any adjustment to paths or environment variables. It also worked without the ".exe" file extension, but it did not work without the "C:\\".

The SetDirectory was only necessary because I used the filename "simple.py". It is also possible to use a relative pathname without SetDirectory. That is, this also worked for me as the first command after launching Mathematica:

RunProcess[{"C:\\IntelPython3\\python.exe", "Python Scripts\\simple.py"}]

In both cases, Python was able to import the NumPy package, create the array and produce the proper output.

Mathematica environment:

When I wrote in the above that it did not work, I should have said the problem was a Mathematica "file not found" error, not a Python message saying that NumPy could not be imported. Here is the environment information you requested:

StringSplit[Environment["PATH"], ";"] // Column
(*

 "C:\\Program Files\\Wolfram \
Research\\Mathematica\\10.1\\SystemFiles\\Libraries\\Windows-x86-64",
 "C:\\Program Files\\Wolfram \
Research\\Mathematica\\10.1\\SystemFiles\\Libraries\\Windows",
 "C:\\Program Files\\Wolfram \
Research\\Mathematica\\10.1\\SystemFiles\\Kernel\\Binaries\\Windows-\
x86-64",
 "C:\\Program Files\\Wolfram Research\\Mathematica\\10.1",
 "C:\\Program Files\\Wolfram \
Research\\Mathematica\\10.1\\SystemFiles\\FrontEnd\\Binaries\\Windows-\
x86-64",
 "C:\\Program Files\\Wolfram \
Research\\Mathematica\\10.1\\SystemFiles\\Kernel\\Binaries\\Windows-\
x86-64",
 "C:\\Windows\\system32",
 "C:\\Windows",
 "C:\\Windows\\System32\\Wbem",
 "C:\\Windows\\System32\\WindowsPowerShell\\v1.0\\"

*)

My Python file

I added code to the Python script to print the environment variable PATH, so here is my script:

try : import os print(os.environ["PATH"]) except : print("no import os, or no PATH") try : import numpy as np b = np.array([1,2,3]) print(b) except : a = "jello world" print(a)

Mathematica evaluation

You will note that IntelPython3 has added two path elements at the beginning of the path:

RunProcess[{"C:\\IntelPython3\\python.exe", "Python Scripts\\simple.py"}]
(*
<|"ExitCode" -> 0,
 "StandardOutput" ->
  "C:\\IntelPython3\\Library\\bin;C:\\IntelPython3\\DLLs;C:\\Program \
Files\\Wolfram \
Research\\Mathematica\\10.1\\SystemFiles\\Libraries\\Windows-x86-64;C:\
\\Program Files\\Wolfram \
Research\\Mathematica\\10.1\\SystemFiles\\Libraries\\Windows;C:\\\
Program Files\\Wolfram \
Research\\Mathematica\\10.1\\SystemFiles\\Kernel\\Binaries\\Windows-\
x86-64;C:\\Program Files\\Wolfram \
Research\\Mathematica\\10.1;C:\\Program Files\\Wolfram \
Research\\Mathematica\\10.1\\SystemFiles\\FrontEnd\\Binaries\\Windows-\
x86-64;C:\\Program Files\\Wolfram \
Research\\Mathematica\\10.1\\SystemFiles\\Kernel\\Binaries\\Windows-\
x86-64;C:\\Windows\\system32;C:\\Windows;C:\\Windows\\System32\\Wbem;\
C:\\Windows\\System32\\WindowsPowerShell\\v1.0\\

  [1 2 3]

  ", "StandardError" -> ""|>
*)