fix pylint errors in CI

- install vtk via pip

cpppetsc/tools/convert_xdmf_to_vtu.py

@@ -18,9 +18,9 @@
 Converts an XDMF file to an ASCII VTU file.
 """
 
-from vtk import vtkXMLUnstructuredGridWriter, vtkXdmfReader
 import argparse
 import pathlib
+from vtk import vtkXMLUnstructuredGridWriter, vtkXdmfReader  # pylint: disable=E0611
 
 
 def parse_input_filename() -> pathlib.Path:
@@ -39,14 +39,14 @@ def main():
     Reads the XDMF file from the path provided via command line argument
     and writes an ASCII VTU file to the same location, but with extension ".vtu".
     """
-    input = parse_input_filename()
-    output = input.stem + ".vtu"
+    in_filename = parse_input_filename()
+    out_filename = in_filename.stem + ".vtu"
 
     reader = vtkXdmfReader()
-    reader.SetFileName(input)
+    reader.SetFileName(in_filename)
     reader.Update()
     writer = vtkXMLUnstructuredGridWriter()
-    writer.SetFileName(output)
+    writer.SetFileName(out_filename)
     writer.SetDataModeToAscii()
     writer.SetInputData(reader.GetOutput())
     writer.Write()

docker/Dockerfile

@@ -19,31 +19,32 @@ FROM $BASE_IMAGE
 ARG PETSC_SCALAR_TYPE=real
 
 RUN apt-get update && \
-        DEBIAN_FRONTEND="noninteractive" \
-        TZ="Europe/Zurich" \
-        apt-get install -y \
-        clang-format \
-        cmake \
-        g++ \
-        git \
-        googletest \
-        libboost-program-options-dev \
-        libeigen3-dev \
-        librange-v3-dev \
-        ninja-build \
-        python3 python3-pip \
-        python3-h5py \
-        gdb
+  DEBIAN_FRONTEND="noninteractive" \
+  TZ="Europe/Zurich" \
+  apt-get install -y \
+  clang-format \
+  cmake \
+  g++ \
+  git \
+  googletest \
+  libboost-program-options-dev \
+  libeigen3-dev \
+  librange-v3-dev \
+  ninja-build \
+  python3 python3-pip \
+  python3-h5py \
+  gdb
 
 RUN pip3 install \
-        mypy==0.790 \
-        black==20.8b1 \
-        pylint==2.6.0 \
-        sympy==1.7.1 \
-        gcovr
+  mypy==0.790 \
+  black==20.8b1 \
+  pylint==2.6.0 \
+  sympy==1.7.1 \
+  vtk==9.1.0 \
+  gcovr
 
 RUN apt-get update && \
-        DEBIAN_FRONTEND="noninteractive" \
-        apt-get install -y \
-        libpetsc-${PETSC_SCALAR_TYPE}-dev \
-        libslepc-${PETSC_SCALAR_TYPE}3.12-dev
\ No newline at end of file
+  DEBIAN_FRONTEND="noninteractive" \
+  apt-get install -y \
+  libpetsc-${PETSC_SCALAR_TYPE}-dev \
+  libslepc-${PETSC_SCALAR_TYPE}3.12-dev
\ No newline at end of file