In what I believe must be a related issue of path configurations, if I build and install pythonnet as above, embedding C# within python works. However, when I attempt to embed python within a C# application:

using(Py.GIL())
{
    dynamic sys = Py.Import("sys");
    sys.path.append(qmlDir);
    QmlPredict = Py.Import("predict");
}

I get the following error:

Unhandled Exception:
System.EntryPointNotFoundException: Py_IsInitialized
  at (wrapper managed-to-native) Python.Runtime.Runtime:Py_IsInitialized ()
  at Python.Runtime.Runtime.Initialize () [0x00000] in <fd547cae3881478db0cb870640e39b43>:0 
  at Python.Runtime.PythonEngine.Initialize (System.Collections.Generic.IEnumerable`1[T] args, System.Boolean setSysArgv) [0x00014] in <fd547cae3881478db0cb870640e39b43>:0 
  at Python.Runtime.PythonEngine.Initialize (System.Boolean setSysArgv) [0x00005] in <fd547cae3881478db0cb870640e39b43>:0 
  at Python.Runtime.PythonEngine.Initialize () [0x00000] in <fd547cae3881478db0cb870640e39b43>:0 
  at Python.Runtime.Py.GIL () [0x00007] in <fd547cae3881478db0cb870640e39b43>:0 

I believe this again must be a path problem related to using a conda python installation, but the solution suggested in this issue #489 did not do the trick for me.

@mikeoconnor0308 have you tried cpython instead of anaconda? There are other problems with conda/anaconda on linux such as this one:

https://groups.google.com/a/continuum.io/forum/#!topic/anaconda/z7RboI3Pir8

Also related issues:

https://github.com/pythonnet/pythonnet/search?q=System.EntryPointNotFoundException%3A+Py_IsInitialized&type=Issues

Using cpython does compile successfully.

I still have the problem of System.EntryPointNotFoundException: Py_IsInitialized, despite trying the solutions proposed in #303 and #489. I could open this as a separate issue?

@mikeoconnor0308 just change the title of this issue and update the headline. can you document which suggestions you tried?

@mikeoconnor0308 did you try this?

#245 (comment)

@denfromufa I have tried the symbolic link suggestion proposed here: #303 (comment)

ln -s /usr/lib/python3.5/config-x86_64-linux-gnu/libpython3.5m.so .

and the LD_PRELOAD method suggested here: #489 (comment)

LD_PRELOAD=/usr/lib/x86_64-linux-gnu/libpython3.5m.so 

finally, i have now tried #245 (comment)

PY_LIBDIR=$(python -c 'import sysconfig; print(sysconfig.get_config_var("LIBDIR"))')
export LD_LIBRARY_PATH=$PY_LIBDIR:$LD_LIBRARY_PATH

None of these tricks resulted in any notable changes, for either the default python3 installed with apt-get, or an anaconda installation. My guess is that during compilation it has not correctly set the libpython library name, or another dependent path is missing? But I do not know how to diagnose it.
The output from a log produced by setting MONO_LOG_LEVEL=debug (attached as csharp_embod.log) is unclear, the issue seems to be:

Mono: DllImport searching in: '__Internal' ('(null)').
Mono: Searching for 'Py_IsInitialized'.
Mono: Probing 'Py_IsInitialized'.
Mono: Could not find 'Py_IsInitialized' due to 'mono: undefined symbol: Py_IsInitialized'.

If we compare that to embedding the CLR in python, (attached as python_clr.log) everything is fine:

Mono: DllImport searching in: '__Internal' ('(null)').
Mono: Searching for 'Py_IsInitialized'.
Mono: Probing 'Py_IsInitialized'.
Mono: Found as 'Py_IsInitialized'.

csharp_embed.log
python_clr.log

@dmitriyse probably understands this more

The problem with the Anaconda Python distribution is that it builds the python.exe statically and additionally provides a dynamic libpython. I'm not quite sure why we even check this at build time, it doesn't make much of a difference IIRC. If you remove the respective section from setup.py (sth with enable_shared) it should work fine.

This is not relevant anymore.