[Python] Make the linter happy about ROOT/__init__.py

bindings/pyroot/pythonizations/python/ROOT/__init__.py

@@ -8,9 +8,21 @@
 # For the list of contributors see $ROOTSYS/README/CREDITS.                    #
 ################################################################################
 
-import importlib
+import atexit
+import builtins
 import os
 import sys
+import types
+from importlib.abc import Loader, MetaPathFinder
+from importlib.machinery import ModuleSpec
+from typing import Optional, Union
+
+import cppyy
+import cppyy.types
+
+from . import _asan  # noqa: F401  # imported for side effects for setup specific to AddressSanitizer environments
+from ._facade import ROOTFacade
+from ._pythonization import _register_pythonizations
 
 # Prevent cppyy's check for extra header directory
 os.environ["CPPYY_API_PATH"] = "none"
@@ -23,32 +35,23 @@
 # the path of the ROOT library directory (only needed on Windows). For example,
 # if the ROOT Python module is in $ROOTSYS/bin/ROOT/__init__.py, the libraries
 # are usually in $ROOTSYS/bin.
-if 'win32' in sys.platform:
-    root_module_path = os.path.dirname(__file__) # expected to be ${CMAKE_INSTALL_PYTHONDIR}/ROOT
-    root_install_pythondir = os.path.dirname(root_module_path) # expected to be ${CMAKE_INSTALL_PYTHONDIR}
+if "win32" in sys.platform:
+    root_module_path = os.path.dirname(__file__)  # expected to be ${CMAKE_INSTALL_PYTHONDIR}/ROOT
+    root_install_pythondir = os.path.dirname(root_module_path)  # expected to be ${CMAKE_INSTALL_PYTHONDIR}
     os.add_dll_directory(root_install_pythondir)
 
-# Do setup specific to AddressSanitizer environments
-from . import _asan
-
-import cppyy
-import cppyy.types
-
 # Build cache of commonly used python strings (the cache is python intern, so
 # all strings are shared python-wide, not just in PyROOT).
 # See: https://docs.python.org/3.2/library/sys.html?highlight=sys.intern#sys.intern
 _cached_strings = []
 for s in ["Branch", "FitFCN", "ROOT", "SetBranchAddress", "SetFCN", "_TClass__DynamicCast", "__class__"]:
     _cached_strings.append(sys.intern(s))
 
-# Trigger the addition of the pythonizations
-from ._pythonization import _register_pythonizations
 
+# Trigger the addition of the pythonizations
 _register_pythonizations()
 
 # Check if we are in the IPython shell
-import builtins
-
 _is_ipython = hasattr(builtins, "__IPYTHON__")
 
 
@@ -72,9 +75,6 @@ def __getitem__(self, _):
 __all__ = _PoisonedDunderAll()
 
 # Configure ROOT facade module
-import sys
-from ._facade import ROOTFacade
-
 _root_facade = ROOTFacade(sys.modules[__name__], _is_ipython)
 sys.modules[__name__] = _root_facade
 
@@ -84,9 +84,6 @@ def __getitem__(self, _):
 #   * https://docs.python.org/3/library/importlib.html#module-importlib.abc
 #
 #   * https://python.plainenglish.io/metapathfinders-or-how-to-change-python-import-behavior-a1cf3b5a13ec
-from importlib.abc import Loader, MetaPathFinder
-from importlib.machinery import ModuleSpec
-from importlib.util import spec_from_loader
 
 
 def _can_be_module(obj) -> bool:
@@ -108,10 +105,6 @@ def _can_be_module(obj) -> bool:
     return False
 
 
-from typing import Optional, Union
-import types
-
-
 def _lookup_root_module(fullname: str) -> Optional[Union[types.ModuleType, cppyy.types.Scope]]:
     """
     Recursively looks up attributes of the ROOT facade, using a full module
@@ -160,6 +153,8 @@ class _RootNamespaceFinder(MetaPathFinder):
     """
 
     def find_spec(self, fullname: str, path, target=None) -> ModuleSpec:
+        from importlib.util import spec_from_loader
+
         if not fullname.startswith("ROOT."):
             # This finder only finds ROOT.*
             return None
@@ -178,11 +173,11 @@ def find_spec(self, fullname: str, path, target=None) -> ModuleSpec:
 
     ip = get_ipython()
     if hasattr(ip, "kernel"):
-        import JupyROOT
+        import JupyROOT  # noqa: F401  # imported the side effect of setting up JupyROOT
+
         # from . import JsMVA
 
 # Register cleanup
-import atexit
 
 
 def cleanup():
@@ -192,4 +187,5 @@ def cleanup():
         facade.__dict__["app"].keep_polling = False
         facade.__dict__["app"].process_root_events.join()
 
+
 atexit.register(cleanup)

bindings/pyroot/pythonizations/python/ROOT/_facade.py

@@ -7,10 +7,6 @@
 import cppyy
 import cppyy.ll
 
-from ._application import PyROOTApplication
-from ._numbadeclare import _NumbaDeclareDecorator
-from ._pythonization import pythonization
-
 
 class PyROOTConfiguration(object):
     """Class for configuring PyROOT"""
@@ -57,6 +53,8 @@ class ROOTFacade(types.ModuleType):
     """Facade class for ROOT module"""
 
     def __init__(self, module, is_ipython):
+        from ._pythonization import pythonization
+
         types.ModuleType.__init__(self, module.__name__)
 
         self.module = module
@@ -181,6 +179,8 @@ def _register_converters_and_executors(self):
             CPyCppyyRegisterExecutorAlias(name, target)
 
     def _finalSetup(self):
+        from ._application import PyROOTApplication
+
         # Prevent this method from being re-entered through the gROOT wrapper
         self.__dict__["gROOT"] = cppyy.gbl.ROOT.GetROOT()
 
@@ -443,6 +443,8 @@ def TMVA(self):
     # Create and overload Numba namespace
     @property
     def Numba(self):
+        from ._numbadeclare import _NumbaDeclareDecorator
+
         cppyy.cppdef("namespace Numba {}")
         ns = self._fallback_getattr("Numba")
         ns.Declare = staticmethod(_NumbaDeclareDecorator)

bindings/pyroot/pythonizations/python/ROOT/_pythonization/__init__.py

@@ -14,8 +14,6 @@
 
 import cppyy
 
-from ._generic import pythonize_generic
-
 # \cond INTERNALS
 gbl_namespace = cppyy.gbl
 # \endcond
@@ -70,6 +68,7 @@ def pythonization(class_name, ns="::", is_prefix=False):
 
         def passes_filter(class_name):
             return any(class_name.startswith(prefix) for prefix in target)
+
     else:
 
         def passes_filter(class_name):
@@ -114,6 +113,7 @@ def cppyy_pythonizor(klass, name):
                 name (string): name of the class that is the current candidate
                     to be pythonized.
             """
+            from ._generic import pythonize_generic
 
             fqn = klass.__cpp_name__
 

bindings/pyroot/pythonizations/python/ROOT/_pythonization/_generic.py

@@ -8,7 +8,6 @@
 # For the list of contributors see $ROOTSYS/README/CREDITS.                    #
 ################################################################################
 
-from ROOT.libROOTPythonizations import AddPrettyPrintingPyz
 
 def _add_getitem_checked(klass):
     # Parameters:
@@ -27,25 +26,28 @@ def getitem_checked(o, i):
         if i >= 0 and i < len(o):
             return o._getitem__unchecked(i)
         else:
-            raise IndexError('index out of range')
+            raise IndexError("index out of range")
 
     klass._getitem__unchecked = klass.__getitem__
     klass.__getitem__ = getitem_checked
 
+
 # Generic pythonizor for pretty printing that is applied to (almost) all classes
 def pythonize_generic(klass, name):
+    from ROOT.libROOTPythonizations import AddPrettyPrintingPyz
+
     # Parameters:
     # klass: class to be pythonized
     # name: string containing the name of the class
 
     # Add pretty printing via setting the __str__ special function
 
     # Exclude classes which have the method __str__ already defined in C++
-    m = getattr(klass, '__str__', None)
-    has_cpp_str = True if m is not None and type(m).__name__ == 'CPPOverload' else False
+    m = getattr(klass, "__str__", None)
+    has_cpp_str = True if m is not None and type(m).__name__ == "CPPOverload" else False
 
     # Exclude std::string with its own pythonization from cppyy
-    exclude = [ 'std::string' ]
+    exclude = ["std::string"]
 
     if name not in exclude and not has_cpp_str:
         AddPrettyPrintingPyz(klass)