Allow passing arguments when entry points are used as functions

ChangeLog

@@ -85,6 +85,11 @@ Release date: TBA
 
   Closes #5504
 
+* When invoking ``pylint``, ``symilar`` or ``pyreverse`` by importing them in a python file
+  you can now pass an ``arguments`` keyword besides patching ``sys.argv``.
+
+  Closes #5320
+
 * The ``PyLinter`` class will now be initialized with a ``TextReporter``
   as its reporter if none is provided.
 

doc/user_guide/run.rst

@@ -45,6 +45,20 @@ thanks to the ``Run()`` function in the ``pylint.lint`` module
   pylint_opts = ['--disable=line-too-long', 'myfile.py']
   pylint.lint.Run(pylint_opts)
 
+Another option would be to use the ``run_pylint`` function, which is the same function
+called by the command line. You can either patch ``sys.argv`` or supply arguments yourself:
+
+.. sourcecode:: python
+
+  import pylint
+
+  sys.argv = ["pylint", "your_file"]
+  pylint.run_pylint()
+
+  # Or:
+
+  pylint.run_pylint(arguments=["your_file"])
+
 To silently run Pylint on a ``module_name.py`` module,
 and get its standard output and error:
 

doc/whatsnew/2.13.rst

@@ -116,6 +116,11 @@ Other Changes
 
   Closes #5557
 
+* When invoking ``pylint``, ``symilar`` or ``pyreverse`` by importing them in a python file
+  you can now pass an ``arguments`` keyword besides patching ``sys.argv``.
+
+  Closes #5320
+
 * The ``PyLinter`` class will now be initialized with a ``TextReporter``
   as its reporter if none is provided.
 

pylint/__init__.py

@@ -11,17 +11,22 @@
 
 import os
 import sys
+from typing import List, Optional
 
 from pylint.__pkginfo__ import __version__
 
 # pylint: disable=import-outside-toplevel
 
 
-def run_pylint():
+def run_pylint(*, arguments: Optional[List[str]] = None):
+    """Run pylint
+
+    Arguments can be a list of strings normally supplied as arguments on the command line
+    """
     from pylint.lint import Run as PylintRun
 
     try:
-        PylintRun(sys.argv[1:])
+        PylintRun(arguments or sys.argv[1:])
     except KeyboardInterrupt:
         sys.exit(1)
 
@@ -32,18 +37,24 @@ def run_epylint():
     EpylintRun()
 
 
-def run_pyreverse():
-    """run pyreverse"""
+def run_pyreverse(*, arguments: Optional[List[str]] = None):
+    """Run pyreverse
+
+    Arguments can be a list of strings normally supplied as arguments on the command line
+    """
     from pylint.pyreverse.main import Run as PyreverseRun
 
-    PyreverseRun(sys.argv[1:])
+    PyreverseRun(arguments or sys.argv[1:])
+
 
+def run_symilar(*, arguments: Optional[List[str]] = None):
+    """Run symilar
 
-def run_symilar():
-    """run symilar"""
+    Arguments can be a list of strings normally supplied as arguments on the command line
+    """
     from pylint.checkers.similar import Run as SimilarRun
 
-    SimilarRun(sys.argv[1:])
+    SimilarRun(arguments or sys.argv[1:])
 
 
 def modify_sys_path() -> None:

tests/test_pylint_runners.py

@@ -21,3 +21,14 @@ def test_runner(runner: Callable, tmpdir: LocalPath) -> None:
             with pytest.raises(SystemExit) as err:
                 runner()
             assert err.value.code == 0
+
+
+@pytest.mark.parametrize("runner", [run_pylint, run_pyreverse, run_symilar])
+def test_runner_with_arguments(runner: Callable, tmpdir: LocalPath) -> None:
+    """Check the runners with arguments as parameter instead of sys.argv"""
+    filepath = os.path.abspath(__file__)
+    testargs = [filepath]
+    with tmpdir.as_cwd():
+        with pytest.raises(SystemExit) as err:
+            runner(arguments=testargs)
+        assert err.value.code == 0