PythonCall.PyNULL causes returned NULL without setting an exception

[dpinol]

Affects: PythonCall used from python

Describe the bug

from juliacall import PythonCall
PythonCall.PyNULL

---------------------------------------------------------------------------
SystemError Traceback (most recent call last)
Cell In[2], line 1
----> 1 PythonCall.PyNULL

File ~/.julia/packages/PythonCall/hXycg/src/JlWrap/any.jl:249, in __getattr__(self, k)
 247 raise AttributeError(k)
 248 else:
--> 249 return self._jl_callmethod($(pyjl_methodnum(pyjlany_getattr)), k)
 250 def __setattr__(self, k, v):
 251 try:

SystemError: <method '_jl_callmethod' of 'juliacall.ValueBase' objects> returned NULL without setting an exception

Your system
Please provide detailed information about your system:

• Ubuntu 25.05
• julia 1.11.6, Python 3.13.7, PythonCall/JuliaCall: 0.9.27
• If an issue with PythonCall, the output of Base.versioninfo(), Pkg.status() and CondaPkg.status().
• juliacall 0.9.27 juliapkg 0.1.17

Commit 9615af0f269 (2025-07-09 12:58 UTC)
Build Info:
 Official https://julialang.org/ release
Platform Info:
 OS: Linux (x86_64-linux-gnu)
 CPU: 32 × 13th Gen Intel(R) Core(TM) i9-13950HX
 WORD_SIZE: 64
 LLVM: libLLVM-16.0.6 (ORCJIT, alderlake)
Threads: 1 default, 0 interactive, 1 GC (on 32 virtual cores)
Environment:
 JULIA_PYTHONCALL_EXE = /home/dani/.virtualenvs/sc-tools--PFlaRe2/bin/python3

Additional context
I don't directly use PythonCall.PyNULL, but I execute PythonCall.getmembers to shim all julia module members in order to access them faster from python.

[cjdoris]

PyNULL is not in the API, it's internal, so you shouldn't be accessing it anyway. So any issues you encounter with it are not a bug.

I'd recommend using names to just access the exported/public members of PythonCall.