# Copyright 2008-2015 Nokia Networks
# Copyright 2016- Robot Framework Foundation
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import os
import sys
import importlib
import inspect
from robot.errors import DataError
from .error import get_error_details
from .robotpath import abspath, normpath
from .robotinspect import is_init
from .robottypes import type_name
[docs]
class Importer:
"""Utility that can import modules and classes based on names and paths.
Imported classes can optionally be instantiated automatically.
"""
def __init__(self, type=None, logger=None):
"""
:param type:
Type of the thing being imported. Used in error and log messages.
:param logger:
Logger to be notified about successful imports and other events.
Currently only needs the ``info`` method, but other level specific
methods may be needed in the future. If not given, logging is disabled.
"""
self._type = type or ''
self._logger = logger or NoLogger()
self._importers = (ByPathImporter(logger),
NonDottedImporter(logger),
DottedImporter(logger))
self._by_path_importer = self._importers[0]
[docs]
def import_class_or_module(self, name_or_path, instantiate_with_args=None,
return_source=False):
"""Imports Python class or module based on the given name or path.
:param name_or_path:
Name or path of the module or class to import.
:param instantiate_with_args:
When arguments are given, imported classes are automatically initialized
using them.
:param return_source:
When true, returns a tuple containing the imported module or class
and a path to it. By default, returns only the imported module or class.
The class or module to import can be specified either as a name, in which
case it must be in the module search path, or as a path to the file or
directory implementing the module. See :meth:`import_class_or_module_by_path`
for more information about importing classes and modules by path.
Classes can be imported from the module search path using name like
``modulename.ClassName``. If the class name and module name are same, using
just ``CommonName`` is enough. When importing a class by a path, the class
name and the module name must match.
Optional arguments to use when creating an instance are given as a list.
Starting from Robot Framework 4.0, both positional and named arguments are
supported (e.g. ``['positional', 'name=value']``) and arguments are converted
automatically based on type hints and default values.
If arguments needed when creating an instance are initially embedded into
the name or path like ``Example:arg1:arg2``, separate
:func:`~robot.utils.text.split_args_from_name_or_path` function can be
used to split them before calling this method.
Use :meth:`import_module` if only a module needs to be imported.
"""
try:
imported, source = self._import(name_or_path)
self._log_import_succeeded(imported, name_or_path, source)
imported = self._instantiate_if_needed(imported, instantiate_with_args)
except DataError as err:
self._raise_import_failed(name_or_path, err)
else:
return self._handle_return_values(imported, source, return_source)
[docs]
def import_module(self, name_or_path):
"""Imports Python module based on the given name or path.
:param name_or_path:
Name or path of the module to import.
The module to import can be specified either as a name, in which
case it must be in the module search path, or as a path to the file or
directory implementing the module. See :meth:`import_class_or_module_by_path`
for more information about importing modules by path.
Use :meth:`import_class_or_module` if it is desired to get a class
from the imported module automatically.
New in Robot Framework 6.0.
"""
try:
imported, source = self._import(name_or_path, get_class=False)
self._log_import_succeeded(imported, name_or_path, source)
except DataError as err:
self._raise_import_failed(name_or_path, err)
else:
return imported
def _import(self, name, get_class=True):
for importer in self._importers:
if importer.handles(name):
return importer.import_(name, get_class)
def _handle_return_values(self, imported, source, return_source=False):
if not return_source:
return imported
if source and os.path.exists(source):
source = self._sanitize_source(source)
return imported, source
def _sanitize_source(self, source):
source = normpath(source)
if os.path.isdir(source):
candidate = os.path.join(source, '__init__.py')
elif source.endswith('.pyc'):
candidate = source[:-4] + '.py'
else:
return source
return candidate if os.path.exists(candidate) else source
[docs]
def import_class_or_module_by_path(self, path, instantiate_with_args=None):
"""Import a Python module or class using a file system path.
:param path:
Path to the module or class to import.
:param instantiate_with_args:
When arguments are given, imported classes are automatically initialized
using them.
When importing a Python file, the path must end with :file:`.py` and the
actual file must also exist.
Use :meth:`import_class_or_module` to support importing also using name,
not only path. See the documentation of that function for more information
about creating instances automatically.
"""
try:
imported, source = self._by_path_importer.import_(path)
self._log_import_succeeded(imported, imported.__name__, source)
return self._instantiate_if_needed(imported, instantiate_with_args)
except DataError as err:
self._raise_import_failed(path, err)
def _log_import_succeeded(self, item, name, source):
import_type = '%s ' % self._type.lower() if self._type else ''
item_type = 'module' if inspect.ismodule(item) else 'class'
location = ("'%s'" % source) if source else 'unknown location'
self._logger.info("Imported %s%s '%s' from %s."
% (import_type, item_type, name, location))
def _raise_import_failed(self, name, error):
prefix = f'Importing {self._type.lower()}' if self._type else 'Importing'
raise DataError(f"{prefix} '{name}' failed: {error.message}")
def _instantiate_if_needed(self, imported, args):
if args is None:
return imported
if inspect.isclass(imported):
return self._instantiate_class(imported, args)
if args:
raise DataError("Modules do not take arguments.")
return imported
def _instantiate_class(self, imported, args):
spec = self._get_arg_spec(imported)
try:
positional, named = spec.resolve(args)
except ValueError as err:
raise DataError(err.args[0])
try:
return imported(*positional, **dict(named))
except Exception:
raise DataError('Creating instance failed: %s\n%s' % get_error_details())
def _get_arg_spec(self, imported):
# Avoid cyclic import. Yuck.
from robot.running.arguments import ArgumentSpec, PythonArgumentParser
init = getattr(imported, '__init__', None)
name = imported.__name__
if not is_init(init):
return ArgumentSpec(name, self._type)
return PythonArgumentParser(self._type).parse(init, name)
class _Importer:
def __init__(self, logger):
self._logger = logger
def _import(self, name, fromlist=None):
if name in sys.builtin_module_names:
raise DataError('Cannot import custom module with same name as '
'Python built-in module.')
importlib.invalidate_caches()
try:
return __import__(name, fromlist=fromlist)
except Exception:
message, traceback = get_error_details(full_traceback=False)
path = '\n'.join(f' {p}' for p in sys.path)
raise DataError(f'{message}\n{traceback}\nPYTHONPATH:\n{path}')
def _verify_type(self, imported):
if inspect.isclass(imported) or inspect.ismodule(imported):
return imported
raise DataError('Expected class or module, got %s.' % type_name(imported))
def _get_class_from_module(self, module, name=None):
klass = getattr(module, name or module.__name__, None)
return klass if inspect.isclass(klass) else None
def _get_source(self, imported):
try:
source = inspect.getfile(imported)
except TypeError:
return None
return abspath(source) if source else None
[docs]
class ByPathImporter(_Importer):
_valid_import_extensions = ('.py', '')
[docs]
def handles(self, path):
return os.path.isabs(path)
[docs]
def import_(self, path, get_class=True):
self._verify_import_path(path)
self._remove_wrong_module_from_sys_modules(path)
imported = self._import_by_path(path)
if get_class:
imported = self._get_class_from_module(imported) or imported
return self._verify_type(imported), path
def _verify_import_path(self, path):
if not os.path.exists(path):
raise DataError('File or directory does not exist.')
if not os.path.isabs(path):
raise DataError('Import path must be absolute.')
if not os.path.splitext(path)[1] in self._valid_import_extensions:
raise DataError('Not a valid file or directory to import.')
def _remove_wrong_module_from_sys_modules(self, path):
importing_from, name = self._split_path_to_module(path)
importing_package = os.path.splitext(path)[1] == ''
if self._wrong_module_imported(name, importing_from, importing_package):
del sys.modules[name]
self._logger.info("Removed module '%s' from sys.modules to import "
"fresh module." % name)
def _split_path_to_module(self, path):
module_dir, module_file = os.path.split(abspath(path))
module_name = os.path.splitext(module_file)[0]
return module_dir, module_name
def _wrong_module_imported(self, name, importing_from, importing_package):
if name not in sys.modules:
return False
source = getattr(sys.modules[name], '__file__', None)
if not source: # play safe
return True
imported_from, imported_package = self._get_import_information(source)
return (normpath(importing_from, case_normalize=True) !=
normpath(imported_from, case_normalize=True) or
importing_package != imported_package)
def _get_import_information(self, source):
imported_from, imported_file = self._split_path_to_module(source)
imported_package = imported_file == '__init__'
if imported_package:
imported_from = os.path.dirname(imported_from)
return imported_from, imported_package
def _import_by_path(self, path):
module_dir, module_name = self._split_path_to_module(path)
sys.path.insert(0, module_dir)
try:
return self._import(module_name)
finally:
sys.path.remove(module_dir)
[docs]
class NonDottedImporter(_Importer):
[docs]
def handles(self, name):
return '.' not in name
[docs]
def import_(self, name, get_class=True):
imported = self._import(name)
if get_class:
imported = self._get_class_from_module(imported) or imported
return self._verify_type(imported), self._get_source(imported)
[docs]
class DottedImporter(_Importer):
[docs]
def handles(self, name):
return '.' in name
[docs]
def import_(self, name, get_class=True):
parent_name, lib_name = name.rsplit('.', 1)
parent = self._import(parent_name, fromlist=[str(lib_name)])
try:
imported = getattr(parent, lib_name)
except AttributeError:
raise DataError("Module '%s' does not contain '%s'."
% (parent_name, lib_name))
if get_class:
imported = self._get_class_from_module(imported, lib_name) or imported
return self._verify_type(imported), self._get_source(imported)
[docs]
class NoLogger:
error = warn = info = debug = trace = lambda self, *args, **kws: None