Rewrite importlib import mechanism

dev/_import.py

@@ -10,7 +10,7 @@
  import imp
 else:
  import importlib
- import importlib.machinery
+ import importlib.abc
  import importlib.util
 
 
@@ -20,6 +20,48 @@
  getcwd = os.getcwd
 
 
+class ModCryptoMetaFinder(importlib.abc.MetaPathFinder):
+ def setup(self):
+ self.modules = {}
+ sys.meta_path.insert(0, self)
+
+ def add_module(self, package_name, package_path):
+ if package_name not in self.modules:
+ self.modules[package_name] = package_path
+
+ def find_spec(self, fullname, path, target=None):
+ name_parts = fullname.split('.')
+ if name_parts[0] not in self.modules:
+ return None
+
+ package = name_parts[0]
+ package_path = self.modules[package]
+
+ fullpath = os.path.join(package_path, *name_parts[1:])
+
+ if os.path.isdir(fullpath):
+ filename = os.path.join(fullpath, "__init__.py")
+ submodule_locations = [fullpath]
+ else:
+ filename = fullpath + ".py"
+ submodule_locations = None
+
+ if not os.path.exists(filename):
+ return None
+
+ return importlib.util.spec_from_file_location(
+ fullname,
+ filename,
+ loader=None,
+ submodule_search_locations=submodule_locations
+ )
+
+
+if sys.version_info >= (3, 5):
+ CUSTOM_FINDER = ModCryptoMetaFinder()
+ CUSTOM_FINDER.setup()
+
+
 def _import_from(mod, path, mod_dir=None, allow_error=False):
  """
  Imports a module from a specific path
@@ -47,16 +89,19 @@ def _import_from(mod, path, mod_dir=None, allow_error=False):
  if mod_dir is None:
  full_mod = mod
  else:
- full_mod = mod_dir
+ full_mod = mod_dir.replace(os.sep, '.')
 
  if mod_dir is None:
  mod_dir = mod.replace('.', os.sep)
 
  if not os.path.exists(path):
  return None
 
- if not os.path.exists(os.path.join(path, mod_dir)) \
- and not os.path.exists(os.path.join(path, mod_dir + '.py')):
+ source_path = os.path.join(path, mod_dir, '__init__.py')
+ if not os.path.exists(source_path):
+ source_path = os.path.join(path, mod_dir + '.py')
+
+ if not os.path.exists(source_path):
  return None
 
  if os.sep in mod_dir:
@@ -69,16 +114,12 @@ def _import_from(mod, path, mod_dir=None, allow_error=False):
  return imp.load_module(mod, *mod_info)
 
  else:
- loader_details = (
- importlib.machinery.SourceFileLoader,
- importlib.machinery.SOURCE_SUFFIXES
- )
- finder = importlib.machinery.FileFinder(path, loader_details)
- spec = finder.find_spec(full_mod)
- module = importlib.util.module_from_spec(spec)
- sys.modules[mod] = module
- spec.loader.exec_module(module)
- return module
+ package = mod.split('.', 1)[0]
+ package_dir = full_mod.split('.', 1)[0]
+ package_path = os.path.join(path, package_dir)
+ CUSTOM_FINDER.add_module(package, package_path)
+
+ return importlib.import_module(mod)
 
  except ImportError:
  if allow_error:

tests/__init__.py

@@ -9,6 +9,50 @@
  import imp
 else:
  import importlib
+ import importlib.abc
+ import importlib.util
+
+
+class ModCryptoMetaFinder(importlib.abc.MetaPathFinder):
+ def setup(self):
+ self.modules = {}
+ sys.meta_path.insert(0, self)
+
+ def add_module(self, package_name, package_path):
+ if package_name not in self.modules:
+ self.modules[package_name] = package_path
+
+ def find_spec(self, fullname, path, target=None):
+ name_parts = fullname.split('.')
+ if name_parts[0] not in self.modules:
+ return None
+
+ package = name_parts[0]
+ package_path = self.modules[package]
+
+ fullpath = os.path.join(package_path, *name_parts[1:])
+
+ if os.path.isdir(fullpath):
+ filename = os.path.join(fullpath, "__init__.py")
+ submodule_locations = [fullpath]
+ else:
+ filename = fullpath + ".py"
+ submodule_locations = None
+
+ if not os.path.exists(filename):
+ return None
+
+ return importlib.util.spec_from_file_location(
+ fullname,
+ filename,
+ loader=None,
+ submodule_search_locations=submodule_locations
+ )
+
+
+if sys.version_info >= (3, 5):
+ CUSTOM_FINDER = ModCryptoMetaFinder()
+ CUSTOM_FINDER.setup()
 
 
 def _import_from(mod, path, mod_dir=None):
@@ -33,29 +77,40 @@ def _import_from(mod, path, mod_dir=None):
  return sys.modules[mod]
 
  if mod_dir is None:
- mod_dir = mod
+ full_mod = mod
+ else:
+ full_mod = mod_dir.replace(os.sep, '.')
+
+ if mod_dir is None:
+ mod_dir = mod.replace('.', os.sep)
 
  if not os.path.exists(path):
  return None
 
- if not os.path.exists(os.path.join(path, mod_dir)):
+ source_path = os.path.join(path, mod_dir, '__init__.py')
+ if not os.path.exists(source_path):
+ source_path = os.path.join(path, mod_dir + '.py')
+
+ if not os.path.exists(source_path):
  return None
 
+ if os.sep in mod_dir:
+ append, mod_dir = mod_dir.rsplit(os.sep, 1)
+ path = os.path.join(path, append)
+
  try:
  if sys.version_info < (3, 5):
  mod_info = imp.find_module(mod_dir, [path])
  return imp.load_module(mod, *mod_info)
+
  else:
- loader_details = (
- importlib.machinery.SourceFileLoader,
- importlib.machinery.SOURCE_SUFFIXES
- )
- finder = importlib.machinery.FileFinder(path, loader_details)
- spec = finder.find_spec(mod_dir)
- module = importlib.util.module_from_spec(spec)
- sys.modules[mod] = module
- spec.loader.exec_module(module)
- return module
+ package = mod.split('.', 1)[0]
+ package_dir = full_mod.split('.', 1)[0]
+ package_path = os.path.join(path, package_dir)
+ CUSTOM_FINDER.add_module(package, package_path)
+
+ return importlib.import_module(mod)
+
  except ImportError:
  return None