[cli] Setup pylint: run 'ti lint' to obtain linting results (#1846)

.pylintrc

@@ -0,0 +1,2 @@
+[MESSAGES CONTROL]
+disable=invalid-name, missing-function-docstring, missing-class-docstring, missing-module-docstring, unused-wildcard-import, cyclic-import, blacklisted-name, import-outside-toplevel

Dockerfile

@@ -25,7 +25,7 @@ RUN apt-get update && \
                        libtinfo5
 
 # Install Taichi's Python dependencies
-RUN python3 -m pip install --user setuptools astpretty astor pybind11 Pillow dill
+RUN python3 -m pip install --user setuptools astor pybind11 pylint sourceinspect
 RUN python3 -m pip install --user pytest pytest-rerunfailures pytest-xdist yapf
 RUN python3 -m pip install --user numpy GitPython coverage colorama autograd
 

Jenkinsfile

@@ -81,7 +81,9 @@ void build_taichi() {
     $CC --version
     $CXX --version
     echo $WORKSPACE
-    $PYTHON_EXECUTABLE -m pip install twine numpy Pillow scipy pybind11 colorama setuptools astor matplotlib pytest autograd GitPython dill --user
+    $PYTHON_EXECUTABLE -m pip install --user setuptools astor pybind11 pylint sourceinspect
+    $PYTHON_EXECUTABLE -m pip install --user pytest pytest-rerunfailures pytest-xdist yapf
+    $PYTHON_EXECUTABLE -m pip install --user numpy GitPython coverage colorama autograd
     export TAICHI_REPO_DIR=$WORKSPACE/
     echo $TAICHI_REPO_DIR
     export PYTHONPATH=$TAICHI_REPO_DIR/python

docs/dev_install.rst

@@ -19,7 +19,7 @@ Installing Dependencies
 
   .. code-block:: bash
 
-    python3 -m pip install --user setuptools astor pybind11 Pillow sourceinspect
+    python3 -m pip install --user setuptools astor pybind11 pylint sourceinspect
     python3 -m pip install --user pytest pytest-rerunfailures pytest-xdist yapf
     python3 -m pip install --user numpy GitPython coverage colorama autograd
 

python/taichi/main.py

@@ -1059,6 +1059,25 @@ def local_scope():
 
         local_scope()
 
+    @register
+    def lint(self, arguments: list = sys.argv[2:]):
+        """Run pylint checker for the Python codebase of Taichi"""
+        parser = argparse.ArgumentParser(prog='ti lint',
+                                         description=f"{self.lint.__doc__}")
+        # TODO: support arguments for lint specific files
+        args = parser.parse_args(arguments)
+
+        options = [os.path.dirname(__file__)]
+
+        from multiprocessing import cpu_count
+        threads = min(8, cpu_count())
+        options += ['-j', str(threads)]
+
+        # http://pylint.pycqa.org/en/latest/user_guide/run.html
+        # TODO: support redirect output to lint.log
+        import pylint.lint
+        pylint.lint.Run(options)
+
 
 def main():
     cli = TaichiMain()