def test_dependencies():
dependencies = {'*nix': ['wmctrl', 'xdotool'],
'python': ['tinydb']}
missing_dependencies = False
dep_err_msgs = []
for dependency in dependencies['*nix']:
DEVNULL = open(os.devnull, 'w')
result = subprocess.call(['which', dependency], stdout=DEVNULL)
if not result == 0:
dep_err_msgs.append('Linux application: ' + dependency)
missing_dependencies = True
for dependency in dependencies['python']:
loader = importlib.find_loader(dependency)
result = loader is not None
if not result:
dep_err_msgs.append('Python package: ' + dependency)
missing_dependencies = True
if missing_dependencies:
print('Worksets will not work - dependencies missing:')
for each in dep_err_msgs:
print(each)
sys.exit()
python类find_loader()的实例源码
def find_module_py33(string, path=None):
loader = importlib.machinery.PathFinder.find_module(string, path)
if loader is None and path is None: # Fallback to find builtins
try:
loader = importlib.find_loader(string)
except ValueError as e:
# See #491. Importlib might raise a ValueError, to avoid this, we
# just raise an ImportError to fix the issue.
raise ImportError("Originally ValueError: " + e.message)
if loader is None:
raise ImportError("Couldn't find a loader for {0}".format(string))
try:
is_package = loader.is_package(string)
if is_package:
module_path = os.path.dirname(loader.path)
module_file = None
else:
module_path = loader.get_filename(string)
module_file = open(module_path, 'rb')
except AttributeError:
# ExtensionLoader has not attribute get_filename, instead it has a
# path attribute that we can use to retrieve the module path
try:
module_path = loader.path
module_file = open(loader.path, 'rb')
except AttributeError:
module_path = string
module_file = None
finally:
is_package = False
return module_file, module_path, is_package
def has_module(module_name):
"""Check to see if a python module is available.
"""
if sys.version_info > (3, ):
import importlib
return importlib.find_loader(module_name) is not None
else: # pragma: no cover
import imp
try:
imp.find_module(module_name)
except ImportError:
return False
return True
def has_module(name):
"""
Check if the Python module 'name' is available.
Parameters
----------
name : str
The name of the Python module, as used in an import instruction.
This function uses ideas from this Stack Overflow question:
http://stackoverflow.com/questions/14050281/
Returns
-------
b : bool
True if the module exists, or False otherwise.
"""
if sys.version_info > (3, 3):
import importlib.util
return importlib.util.find_spec(name) is not None
elif sys.version_info > (2, 7, 99):
import importlib
return importlib.find_loader(name) is not None
else:
import pkgutil
return pkgutil.find_loader(name) is not None
def check_if_installed(module_name):
try:
module_status = importlib.find_loader(module_name)
except Exception:
module_status = importlib.util.find_spec(module_name)
return module_status
def can_import(name, package=None):
""" Returns True if the given module can be imported.
# Arguments
name: str. The name of the module.
package: str. The name of the package, if `name` is a relative import.
This is ignored for Python versions < 3.4.
# Return value
If importing the specified module should succeed, returns True;
otherwise, returns False.
"""
try:
importlib.util.find_spec
except AttributeError:
# Python < 3.4
return importlib.find_loader( # pylint: disable=deprecated-method
name
) is not None
else:
# Python >= 3.4
return importlib.util.find_spec(name, package=package) is not None
### EOF.EOF.EOF.EOF.EOF.EOF.EOF.EOF.EOF.EOF.EOF.EOF.EOF.EOF.EOF.EOF.EOF.EOF.EOF
def install_package(_package_name, _arguments=None):
"""
Install the packages listed if not present
:param _package_name: The package to install
:param _argument: An optional argument
:return:
"""
_installed = []
import pip
_exists = None
if minor < 3:
import pkgutil
_exists = pkgutil.find_loader(_package_name)
elif minor == 3:
import importlib
_exists = importlib.find_loader(_package_name)
else:
import importlib
_exists = importlib.util.find_spec(_package_name)
if _exists is None:
print(_package_name + " not installed, installing...")
if _arguments is None:
pip.main(['install', _package_name])
else:
pip.main(['install', _package_name] + _arguments)
print(_package_name + " installed...")
return True
else:
print(_package_name + " already installed, skipping...")
return False
def test_sys_modules(self):
# If a module with __loader__ is in sys.modules, then return it.
name = 'some_mod'
with util.uncache(name):
module = imp.new_module(name)
loader = 'a loader!'
module.__loader__ = loader
sys.modules[name] = module
found = importlib.find_loader(name)
self.assertEqual(loader, found)
def test_sys_modules_loader_is_None(self):
# If sys.modules[name].__loader__ is None, raise ValueError.
name = 'some_mod'
with util.uncache(name):
module = imp.new_module(name)
module.__loader__ = None
sys.modules[name] = module
with self.assertRaises(ValueError):
importlib.find_loader(name)
def test_success(self):
# Return the loader found on sys.meta_path.
name = 'some_mod'
with util.uncache(name):
with util.import_state(meta_path=[self.FakeMetaFinder]):
self.assertEqual((name, None), importlib.find_loader(name))
def test_success_path(self):
# Searching on a path should work.
name = 'some_mod'
path = 'path to some place'
with util.uncache(name):
with util.import_state(meta_path=[self.FakeMetaFinder]):
self.assertEqual((name, path),
importlib.find_loader(name, path))
def test_nothing(self):
# None is returned upon failure to find a loader.
self.assertIsNone(importlib.find_loader('nevergoingtofindthismodule'))
def find_module_py33(string, path=None):
loader = importlib.machinery.PathFinder.find_module(string, path)
if loader is None and path is None: # Fallback to find builtins
loader = importlib.find_loader(string)
if loader is None:
raise ImportError("Couldn't find a loader for {0}".format(string))
try:
is_package = loader.is_package(string)
if is_package:
module_path = os.path.dirname(loader.path)
module_file = None
else:
module_path = loader.get_filename(string)
module_file = open(module_path, 'rb')
except AttributeError:
# ExtensionLoader has not attribute get_filename, instead it has a
# path attribute that we can use to retrieve the module path
try:
module_path = loader.path
module_file = open(loader.path, 'rb')
except AttributeError:
module_path = string
module_file = None
finally:
is_package = False
return module_file, module_path, is_package
def can_import(name, package=None):
""" Returns True if the given module can be imported.
# Arguments
name: str. The name of the module.
package: str. The name of the package, if `name` is a relative import.
This is ignored for Python versions < 3.4.
# Return value
If importing the specified module should succeed, returns True;
otherwise, returns False.
"""
try:
importlib.util.find_spec
except AttributeError:
# Python < 3.4
return importlib.find_loader( # pylint: disable=deprecated-method
name
) is not None
else:
# Python >= 3.4
return importlib.util.find_spec(name, package=package) is not None
### EOF.EOF.EOF.EOF.EOF.EOF.EOF.EOF.EOF.EOF.EOF.EOF.EOF.EOF.EOF.EOF.EOF.EOF.EOF
def find_module_py33(string, path=None, loader=None, fullname=None):
loader = loader or importlib.machinery.PathFinder.find_module(string, path)
if loader is None and path is None: # Fallback to find builtins
try:
with warnings.catch_warnings(record=True):
# Mute "DeprecationWarning: Use importlib.util.find_spec()
# instead." While we should replace that in the future, it's
# probably good to wait until we deprecate Python 3.3, since
# it was added in Python 3.4 and find_loader hasn't been
# removed in 3.6.
loader = importlib.find_loader(string)
except ValueError as e:
# See #491. Importlib might raise a ValueError, to avoid this, we
# just raise an ImportError to fix the issue.
raise ImportError("Originally " + repr(e))
if loader is None:
raise ImportError("Couldn't find a loader for {0}".format(string))
try:
is_package = loader.is_package(string)
if is_package:
if hasattr(loader, 'path'):
module_path = os.path.dirname(loader.path)
else:
# At least zipimporter does not have path attribute
module_path = os.path.dirname(loader.get_filename(string))
if hasattr(loader, 'archive'):
module_file = DummyFile(loader, string)
else:
module_file = None
else:
module_path = loader.get_filename(string)
module_file = DummyFile(loader, string)
except AttributeError:
# ExtensionLoader has not attribute get_filename, instead it has a
# path attribute that we can use to retrieve the module path
try:
module_path = loader.path
module_file = DummyFile(loader, string)
except AttributeError:
module_path = string
module_file = None
finally:
is_package = False
if hasattr(loader, 'archive'):
module_path = loader.archive
return module_file, module_path, is_package
def find_module_py33(string, path=None):
loader = importlib.machinery.PathFinder.find_module(string, path)
if loader is None and path is None: # Fallback to find builtins
try:
loader = importlib.find_loader(string)
except ValueError as e:
# See #491. Importlib might raise a ValueError, to avoid this, we
# just raise an ImportError to fix the issue.
raise ImportError("Originally " + repr(e))
if loader is None:
raise ImportError("Couldn't find a loader for {0}".format(string))
try:
is_package = loader.is_package(string)
if is_package:
if hasattr(loader, 'path'):
module_path = os.path.dirname(loader.path)
else:
# At least zipimporter does not have path attribute
module_path = os.path.dirname(loader.get_filename(string))
if hasattr(loader, 'archive'):
module_file = DummyFile(loader, string)
else:
module_file = None
else:
module_path = loader.get_filename(string)
module_file = DummyFile(loader, string)
except AttributeError:
# ExtensionLoader has not attribute get_filename, instead it has a
# path attribute that we can use to retrieve the module path
try:
module_path = loader.path
module_file = DummyFile(loader, string)
except AttributeError:
module_path = string
module_file = None
finally:
is_package = False
if hasattr(loader, 'archive'):
module_path = loader.archive
return module_file, module_path, is_package
def find_module(self, fullname, path=None):
# If the module being imported is not one we have registered
# post import hooks for, we can return immediately. We will
# take no further part in the importing of this module.
if not fullname in _post_import_hooks:
return None
# When we are interested in a specific module, we will call back
# into the import system a second time to defer to the import
# finder that is supposed to handle the importing of the module.
# We set an in progress flag for the target module so that on
# the second time through we don't trigger another call back
# into the import system and cause a infinite loop.
if fullname in self.in_progress:
return None
self.in_progress[fullname] = True
# Now call back into the import system again.
try:
if PY3:
# For Python 3 we need to use find_loader() from
# the importlib module. It doesn't actually
# import the target module and only finds the
# loader. If a loader is found, we need to return
# our own loader which will then in turn call the
# real loader to import the module and invoke the
# post import hooks.
loader = importlib.find_loader(fullname, path)
if loader:
return _ImportHookChainedLoader(loader)
else:
# For Python 2 we don't have much choice but to
# call back in to __import__(). This will
# actually cause the module to be imported. If no
# module could be found then ImportError will be
# raised. Otherwise we return a loader which
# returns the already loaded module and invokes
# the post import hooks.
__import__(fullname)
return _ImportHookLoader()
finally:
del self.in_progress[fullname]
# Decorator for marking that a function should be called as a post
# import hook when the target module is imported.
def find_module_py33(string, path=None, loader=None, fullname=None):
loader = loader or importlib.machinery.PathFinder.find_module(string, path)
if loader is None and path is None: # Fallback to find builtins
try:
loader = importlib.find_loader(string)
except ValueError as e:
# See #491. Importlib might raise a ValueError, to avoid this, we
# just raise an ImportError to fix the issue.
raise ImportError("Originally " + repr(e))
if loader is None:
raise ImportError("Couldn't find a loader for {0}".format(string))
try:
is_package = loader.is_package(string)
if is_package:
if hasattr(loader, 'path'):
module_path = os.path.dirname(loader.path)
else:
# At least zipimporter does not have path attribute
module_path = os.path.dirname(loader.get_filename(string))
if hasattr(loader, 'archive'):
module_file = DummyFile(loader, string)
else:
module_file = None
else:
module_path = loader.get_filename(string)
module_file = DummyFile(loader, string)
except AttributeError:
# ExtensionLoader has not attribute get_filename, instead it has a
# path attribute that we can use to retrieve the module path
try:
module_path = loader.path
module_file = DummyFile(loader, string)
except AttributeError:
module_path = string
module_file = None
finally:
is_package = False
if hasattr(loader, 'archive'):
module_path = loader.archive
return module_file, module_path, is_package
def find_module(self, fullname, path=None):
# If the module being imported is not one we have registered
# post import hooks for, we can return immediately. We will
# take no further part in the importing of this module.
if not fullname in _post_import_hooks:
return None
# When we are interested in a specific module, we will call back
# into the import system a second time to defer to the import
# finder that is supposed to handle the importing of the module.
# We set an in progress flag for the target module so that on
# the second time through we don't trigger another call back
# into the import system and cause a infinite loop.
if fullname in self.in_progress:
return None
self.in_progress[fullname] = True
# Now call back into the import system again.
try:
if PY3:
# For Python 3 we need to use find_loader() from
# the importlib module. It doesn't actually
# import the target module and only finds the
# loader. If a loader is found, we need to return
# our own loader which will then in turn call the
# real loader to import the module and invoke the
# post import hooks.
loader = importlib.find_loader(fullname, path)
if loader:
return _ImportHookChainedLoader(loader)
else:
# For Python 2 we don't have much choice but to
# call back in to __import__(). This will
# actually cause the module to be imported. If no
# module could be found then ImportError will be
# raised. Otherwise we return a loader which
# returns the already loaded module and invokes
# the post import hooks.
__import__(fullname)
return _ImportHookLoader()
finally:
del self.in_progress[fullname]
# Decorator for marking that a function should be called as a post
# import hook when the target module is imported.
def find_module_py33(string, path=None):
loader = importlib.machinery.PathFinder.find_module(string, path)
if loader is None and path is None: # Fallback to find builtins
try:
loader = importlib.find_loader(string)
except ValueError as e:
# See #491. Importlib might raise a ValueError, to avoid this, we
# just raise an ImportError to fix the issue.
raise ImportError("Originally " + repr(e))
if loader is None:
raise ImportError("Couldn't find a loader for {0}".format(string))
try:
is_package = loader.is_package(string)
if is_package:
if hasattr(loader, 'path'):
module_path = os.path.dirname(loader.path)
else:
# At least zipimporter does not have path attribute
module_path = os.path.dirname(loader.get_filename(string))
if hasattr(loader, 'archive'):
module_file = DummyFile(loader, string)
else:
module_file = None
else:
module_path = loader.get_filename(string)
module_file = DummyFile(loader, string)
except AttributeError:
# ExtensionLoader has not attribute get_filename, instead it has a
# path attribute that we can use to retrieve the module path
try:
module_path = loader.path
module_file = DummyFile(loader, string)
except AttributeError:
module_path = string
module_file = None
finally:
is_package = False
if hasattr(loader, 'archive'):
module_path = loader.archive
return module_file, module_path, is_package
def find_module_py33(string, path=None, loader=None, fullname=None):
loader = loader or importlib.machinery.PathFinder.find_module(string, path)
if loader is None and path is None: # Fallback to find builtins
try:
loader = importlib.find_loader(string)
except ValueError as e:
# See #491. Importlib might raise a ValueError, to avoid this, we
# just raise an ImportError to fix the issue.
raise ImportError("Originally " + repr(e))
if loader is None:
raise ImportError("Couldn't find a loader for {0}".format(string))
try:
is_package = loader.is_package(string)
if is_package:
if hasattr(loader, 'path'):
module_path = os.path.dirname(loader.path)
else:
# At least zipimporter does not have path attribute
module_path = os.path.dirname(loader.get_filename(string))
if hasattr(loader, 'archive'):
module_file = DummyFile(loader, string)
else:
module_file = None
else:
module_path = loader.get_filename(string)
module_file = DummyFile(loader, string)
except AttributeError:
# ExtensionLoader has not attribute get_filename, instead it has a
# path attribute that we can use to retrieve the module path
try:
module_path = loader.path
module_file = DummyFile(loader, string)
except AttributeError:
module_path = string
module_file = None
finally:
is_package = False
if hasattr(loader, 'archive'):
module_path = loader.archive
return module_file, module_path, is_package
def find_module_py33(string, path=None, loader=None, fullname=None):
loader = loader or importlib.machinery.PathFinder.find_module(string, path)
if loader is None and path is None: # Fallback to find builtins
try:
loader = importlib.find_loader(string)
except ValueError as e:
# See #491. Importlib might raise a ValueError, to avoid this, we
# just raise an ImportError to fix the issue.
raise ImportError("Originally " + repr(e))
if loader is None:
raise ImportError("Couldn't find a loader for {0}".format(string))
try:
is_package = loader.is_package(string)
if is_package:
if hasattr(loader, 'path'):
module_path = os.path.dirname(loader.path)
else:
# At least zipimporter does not have path attribute
module_path = os.path.dirname(loader.get_filename(string))
if hasattr(loader, 'archive'):
module_file = DummyFile(loader, string)
else:
module_file = None
else:
module_path = loader.get_filename(string)
module_file = DummyFile(loader, string)
except AttributeError:
# ExtensionLoader has not attribute get_filename, instead it has a
# path attribute that we can use to retrieve the module path
try:
module_path = loader.path
module_file = DummyFile(loader, string)
except AttributeError:
module_path = string
module_file = None
finally:
is_package = False
if hasattr(loader, 'archive'):
module_path = loader.archive
return module_file, module_path, is_package
