Model training walkthrough produces: Fatal error: 'try!' expression unexpectedly raised an error: Python exception: No module named 'matplotlib'

[arielelkin]

I'm following the Tensorflow Model training walkthrough, but I'm getting a runtime error very early on, at this line:

import TensorFlow
import PythonKit

let plt = Python.import("matplotlib.pyplot")

the error is:

Fatal error: 'try!' expression unexpectedly raised an error: Python exception: No module named 'matplotlib': file PythonKit/Python.swift, line 673
2020-11-17 17:58:46.218246+0100 TensorMac[44863:607287] Fatal error: 'try!' expression unexpectedly raised an error: Python exception: No module named 'matplotlib': file PythonKit/Python.swift, line 673

I'm running Xcode 12.1, have followed all the steps in Installation.md and installed the Swift for TensorFlow 0.11 Release Xcode toolchain.

I'm able to import those libraries from the Pyton REPL:

$ python
Python 2.7.16 (default, Jun  5 2020, 22:59:21) 
[GCC 4.2.1 Compatible Apple LLVM 11.0.3 (clang-1103.0.29.20) (-macos10.15-objc- on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import numpy
>>> import matplotlib
>>> 

Any thoughts?

[brettkoonce]

Loosely, xcode is using the system python and you are running a different version in your terminal:

let os = Python.import("os")
print(os.playgroundDescription)

 <module 'os' from '/usr/local/Frameworks/Python.framework/Versions/3.8/lib/python3.8/os.py'>

install matplotlib with this version:

/usr/local/Frameworks/Python.framework/Versions/3.8/bin/python3 -m pip install matplotlib

[arielelkin]

Thanks for the pointer. I ended up fixing this by installing Python 3 and then doing $ pip3 install matplotlib