The z3 python module loads libz3.so.  This is the link file of the z3 package, not the runtime file.  It is therefore provided in z3-devel.

There is the question whether the Python module should indeed depend on the ABI version as specified in the full runtime name: libz3.so.4.12.  In that case the loader code must use the correct file name but nothing else needs to change.

Alternatively, the Python module can continue to use libz3.so as the file name.  But then it is necessary to add z3-devel to the dependencies of python3-z3.

Reproducible: Always

Steps to Reproduce:
1.make sure z3-devel is not installed but python3-z3 is installed
2.start python
3.type 'import z3'
Actual Results:  
>>> import z3
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ModuleNotFoundError: No module named 'z3'
>>> import z3py
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ModuleNotFoundError: No module named 'z3py'
>>> import pyz3
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ModuleNotFoundError: No module named 'pyz3'


Expected Results:  
module is loaded normally