# There is some problem in my software mistakenly help me!

from dolfin import *

# Create mesh and define function space
mesh = UnitSquareMesh(32, 32)
V = FunctionSpace(mesh, "Lagrange", 1)

# Define Dirichlet boundary (x = 0 or x = 1)
def boundary(x):
return x[0] < DOLFIN_EPS or x[0] > 1.0 - DOLFIN_EPS

# Define boundary condition
u0 = Constant(0.0)
bc = DirichletBC(V, u0, boundary)

# Define variational problem
u = TrialFunction(V)
v = TestFunction(V)
f = Expression("10*exp(-(pow(x[0] - 0.5, 2) + pow(x[1] - 0.5, 2)) / 0.02)")
g = Expression("sin(5*x[0])")
L = f*v*dx + g*v*ds

# Compute solution
u = Function(V)
solve(a == L, u, bc)


error:

File "/home/ayush/poisson.py", line 1, in <module>
from dolfin import *
File "/usr/lib/petsc/lib/python3/dist-packages/dolfin/__init__.py", line 138, in <module>
from . import parameter
File "/usr/lib/petsc/lib/python3/dist-packages/dolfin/parameter/__init__.py", line 11, in <module>
from ffc import default_jit_parameters
File "/home/ayush/.local/lib/python3.10/site-packages/ffc/__init__.py", line 24, in <module>
from ffc.compiler import compile_form, compile_element
File "/home/ayush/.local/lib/python3.10/site-packages/ffc/compiler.py", line 129, in <module>
from ffc.codegeneration import generate_code
File "/home/ayush/.local/lib/python3.10/site-packages/ffc/codegeneration.py", line 37, in <module>
import ffc.uflacs.language.cnodes as L
File "/home/ayush/.local/lib/python3.10/site-packages/ffc/uflacs/__init__.py", line 23, in <module>
from ffc.uflacs.uflacsrepresentation import compute_integral_ir
File "/home/ayush/.local/lib/python3.10/site-packages/ffc/uflacs/uflacsrepresentation.py", line 26, in <module>
from ffc.representationutils import initialize_integral_ir
File "/home/ayush/.local/lib/python3.10/site-packages/ffc/representationutils.py", line 28, in <module>
from ufl.cell import cellname2facetname
ImportError: cannot import name 'cellname2facetname' from 'ufl.cell' (/usr/lib/python3/dist-packages/ufl/cell.py)


You have an incompatible version of ffc/ufl installed, Ref

ayush@ayush-Precision-5820-Tower:~$python3 poisson.py Traceback (most recent call last): File "/home/ayush/poisson.py", line 1, in <module> from fenics import * ModuleNotFoundError: No module named 'fenics'  You have not stated what commands you have executed to remove the offending module, or how you installed dolfin in the first place. Please consider that you need to add the context of your error messages to your post, not just post the error message. i don’t know intermediate steps. Now the error is ayush@ayush-Precision-5820-Tower:~$ fenics-version
2019.2.0.dev0
ayush@ayush-Precision-5820-Tower:~$dolfin- dolfin-convert dolfin-get-demos dolfin-order dolfin-plot dolfin-version ayush@ayush-Precision-5820-Tower:~$ ufl
command 'ufw' from snap ufw (0.36.2)
command 'ofl' from deb hxtools (20211204-1)
command 'uil' from deb uil (2.3.8-3)
command 'ul' from deb bsdextrautils (2.38-4ubuntu1)
command 'ufw' from deb ufw (0.36.1-4build1)
See 'snap info <snapname>' for additional versions.
ayush@ayush-Precision-5820-Tower:~$python3 Python 3.10.7 (main, Mar 10 2023, 10:47:39) [GCC 12.2.0] on linux Type "help", "copyright", "credits" or "license" for more information. >>> [10]+ Stopped python3 ayush@ayush-Precision-5820-Tower:~$ python3 poisson.py
hwloc/linux: Ignoring PCI device with non-16bit domain.
Pass --enable-32bits-pci-domain to configure to support such devices
(warning: it would break the library ABI, don't enable unless really needed).
hwloc/linux: Ignoring PCI device with non-16bit domain.
Pass --enable-32bits-pci-domain to configure to support such devices
(warning: it would break the library ABI, don't enable unless really needed).
Traceback (most recent call last):
File "/home/ayush/poisson.py", line 1, in <module>
from fenics import *
File "/usr/lib/python3/dist-packages/fenics/__init__.py", line 7, in <module>
from dolfin import *
File "/usr/lib/petsc/lib/python3/dist-packages/dolfin/__init__.py", line 144, in <module>
from .fem.assembling import (assemble, assemble_system, assemble_multimesh, assemble_mixed,
File "/usr/lib/petsc/lib/python3/dist-packages/dolfin/fem/assembling.py", line 38, in <module>
from ufl.form import sub_forms_by_domain
ImportError: cannot import name 'sub_forms_by_domain' from 'ufl.form' (/home/ayush/.local/lib/python3.10/site-packages/ufl/form.py)
ayush@ayush-Precision-5820-Tower:~\$



i also try in the same way given in the above post but it is not resolve. tell me the steps how I can uninstall everything and install fenics again

May be that information provide some idea to you in order to help me

How did you install dolfin in the first place, and how did you install ufl?

If you dont know how you installed ufl or dolfin, i cannot help you uninstall it.