Import error

[Amin Sadeghi]

Hi,

When I try from petsc4py import PETSc I get this error:

AttributeError: type object 'petsc4py.PETSc.array' has no attribute 'reduce_cython'

I would appreciate it if someone could let me know what went wrong.

[Amin Sadeghi]

Update 1: After I uninstalled mumps, I got the following error when trying to import PETSc:

>>> from petsc4py import PETSc
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/amin/anaconda3/envs/pmeal/lib/python3.7/site-packages/petsc4py/PETSc.py", line 3, in <module>
    PETSc = ImportPETSc(ARCH)
  File "/home/amin/anaconda3/envs/pmeal/lib/python3.7/site-packages/petsc4py/lib/__init__.py", line 29, in ImportPETSc
    return Import('petsc4py', 'PETSc', path, arch)
  File "/home/amin/anaconda3/envs/pmeal/lib/python3.7/site-packages/petsc4py/lib/__init__.py", line 73, in Import
    module = import_module(pkg, name, path, arch)
  File "/home/amin/anaconda3/envs/pmeal/lib/python3.7/site-packages/petsc4py/lib/__init__.py", line 58, in import_module
    with f: return imp.load_module(fullname, f, fn, info)
  File "/home/amin/anaconda3/envs/pmeal/lib/python3.7/imp.py", line 242, in load_module
    return load_dynamic(name, filename, file)
  File "/home/amin/anaconda3/envs/pmeal/lib/python3.7/imp.py", line 342, in load_dynamic
    return _load(spec)
  File "PETSc/PETSc.pyx", line 111, in init petsc4py.PETSc
ModuleNotFoundError: No module named 'numpy.core._multiarray_umath'

‌

[Amin Sadeghi]

Update 2: I’m almost sure that mumps package is the culprit. After uninstalling mumps, I reinstalled numpy ans scipy and then I could import PETSc without any trouble. So, I guess installing mumps causes some dependency mismatch.

[Lisandro Dalcin]

Maybe the mumps package is outdated and has to be rebuilt. But this is not the right place to discuss these installations issues, you should use the conda-forge/petsc4py-feedstock in github, and post the full output of conda install petsc4py in a fresh environment.