|
| 1 | +import os |
| 2 | +import sys |
| 3 | +from importlib import import_module |
| 4 | +from importlib.util import find_spec as importlib_find |
| 5 | + |
| 6 | + |
| 7 | +def cached_import(module_path, class_name): |
| 8 | + """ |
| 9 | + Credit: https://github.com/django/django/blob/4.0.4/django/utils/module_loading.py |
| 10 | + """ |
| 11 | + modules = sys.modules |
| 12 | + if module_path not in modules or ( |
| 13 | + # Module is not fully initialized. |
| 14 | + getattr(modules[module_path], "__spec__", None) is not None |
| 15 | + and getattr(modules[module_path].__spec__, "_initializing", False) is True |
| 16 | + ): |
| 17 | + import_module(module_path) |
| 18 | + return getattr(modules[module_path], class_name) |
| 19 | + |
| 20 | + |
| 21 | +def import_string(dotted_path): |
| 22 | + """ |
| 23 | + Import a dotted module path and return the attribute/class designated by the |
| 24 | + last name in the path. Raise ImportError if the import failed. |
| 25 | +
|
| 26 | + Credit: https://github.com/django/django/blob/4.0.4/django/utils/module_loading.py |
| 27 | + """ |
| 28 | + try: |
| 29 | + module_path, class_name = dotted_path.rsplit(".", 1) |
| 30 | + except ValueError as err: |
| 31 | + raise ImportError("%s doesn't look like a module path" % dotted_path) from err |
| 32 | + |
| 33 | + try: |
| 34 | + return cached_import(module_path, class_name) |
| 35 | + except AttributeError as err: |
| 36 | + raise ImportError( |
| 37 | + 'Module "%s" does not define a "%s" attribute/class' |
| 38 | + % (module_path, class_name) |
| 39 | + ) from err |
| 40 | + |
| 41 | + |
| 42 | +def module_has_submodule(package, module_name): |
| 43 | + """See if 'module' is in 'package'. |
| 44 | +
|
| 45 | + Credit: https://github.com/django/django/blob/4.0.4/django/utils/module_loading.py |
| 46 | + """ |
| 47 | + try: |
| 48 | + package_name = package.__name__ |
| 49 | + package_path = package.__path__ |
| 50 | + except AttributeError: |
| 51 | + # package isn't a package. |
| 52 | + return False |
| 53 | + |
| 54 | + full_module_name = package_name + "." + module_name |
| 55 | + try: |
| 56 | + return importlib_find(full_module_name, package_path) is not None |
| 57 | + except ModuleNotFoundError: |
| 58 | + # When module_name is an invalid dotted path, Python raises |
| 59 | + # ModuleNotFoundError. |
| 60 | + return False |
| 61 | + |
| 62 | + |
| 63 | +def module_dir(module): |
| 64 | + """ |
| 65 | + Find the name of the directory that contains a module, if possible. |
| 66 | +
|
| 67 | + Raise ValueError otherwise, e.g. for namespace packages that are split |
| 68 | + over several directories. |
| 69 | +
|
| 70 | + Credit: https://github.com/django/django/blob/4.0.4/django/utils/module_loading.py |
| 71 | + """ |
| 72 | + # Convert to list because __path__ may not support indexing. |
| 73 | + paths = list(getattr(module, "__path__", [])) |
| 74 | + if len(paths) == 1: |
| 75 | + return paths[0] |
| 76 | + else: |
| 77 | + filename = getattr(module, "__file__", None) |
| 78 | + if filename is not None: |
| 79 | + return os.path.dirname(filename) |
| 80 | + raise ValueError("Cannot determine directory containing %s" % module) |
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