{"record":{"id":"8fddface7b8aa965","repo":"pallets/flask","slug":"no-root-path-can-be-found-for-the-provided-module","errorCode":null,"errorMessage":"No root path can be found for the provided module {import_name!r}. This can happen because the module came from an import hook that does not provide file name information or because it's a namespace package. In this case the root path needs to be explicitly provided.","messagePattern":"No root path can be found for the provided module (.+?)\\. This can happen because the module came from an import hook that does not provide file name information or because it's a namespace package\\. In this case the root path needs to be explicitly provided\\.","errorType":"exception","errorClass":"RuntimeError","httpStatus":null,"severity":"error","filePath":"src/flask/helpers.py","lineNumber":631,"sourceCode":"    # Loader does not exist or we're referring to an unloaded main\n    # module or a main module without path (interactive sessions), go\n    # with the current working directory.\n    if loader is None:\n        return os.getcwd()\n\n    if hasattr(loader, \"get_filename\"):\n        filepath = loader.get_filename(import_name)  # pyright: ignore\n    else:\n        # Fall back to imports.\n        __import__(import_name)\n        mod = sys.modules[import_name]\n        filepath = getattr(mod, \"__file__\", None)\n\n        # If we don't have a file path it might be because it is a\n        # namespace package. In this case pick the root path from the\n        # first module that is contained in the package.\n        if filepath is None:\n            raise RuntimeError(\n                \"No root path can be found for the provided module\"\n                f\" {import_name!r}. This can happen because the module\"\n                \" came from an import hook that does not provide file\"\n                \" name information or because it's a namespace package.\"\n                \" In this case the root path needs to be explicitly\"\n                \" provided.\"\n            )\n\n    # filepath is import_name.py for a module, or __init__.py for a package.\n    return os.path.dirname(os.path.abspath(filepath))  # type: ignore[no-any-return]\n\n\n@cache\ndef _split_blueprint_path(name: str) -> list[str]:\n    out: list[str] = [name]\n\n    if \".\" in name:\n        out.extend(_split_blueprint_path(name.rpartition(\".\")[0]))","sourceCodeStart":613,"sourceCodeEnd":649,"githubUrl":"https://github.com/pallets/flask/blob/3596b1ab61cea85edb8970e83ff61daa073facf8/src/flask/helpers.py#L613-L649","documentation":"get_root_path(import_name) tries loader.get_filename(import_name); if the loader lacks that method it falls back to __import__ and reads mod.__file__. If __file__ is None (the module is a namespace package or came from an import hook that supplies no file info), it raises RuntimeError telling you to provide the root path explicitly.","triggerScenarios":"Creating a Flask(import_name=...) where import_name resolves to a namespace package (PEP 420, no __init__.py) or a module loaded by a custom importer/meta-path hook that does not set __file__. Because no filesystem path can be derived, Flask cannot compute the root path for static files and templates.","commonSituations":"Using Flask in a namespace package layout. Dynamically importing the app module via a custom loader. Calling Flask('') or Flask with a name that maps to a synthetic module. Migrating to a src/ layout where the package becomes a namespace package by accident (missing __init__.py).","solutions":["Pass an explicit root_path to Flask: Flask(__name__, root_path='/abs/path/to/app').","Ensure your package has an __init__.py so it is a regular package with a real __file__.","Pass a concrete module/file path as import_name rather than a namespace package name."],"exampleFix":"# before\napp = Flask('my_namespace_pkg')  # namespace package, __file__ is None\n\n# after\napp = Flask('my_namespace_pkg', root_path=os.path.dirname(__file__))\n# or ensure the package has __init__.py","handlingStrategy":"validation","validationCode":"import importlib.util, os\n\ndef has_root_path(import_name: str) -> bool:\n    spec = importlib.util.find_spec(import_name)\n    if spec is None:\n        return False\n    return bool(spec.origin) and spec.origin != 'namespace'","typeGuard":"import importlib.util\n\ndef is_regular_package(import_name: str) -> bool:\n    spec = importlib.util.find_spec(import_name)\n    return spec is not None and bool(spec.submodule_search_locations is None)","tryCatchPattern":"try:\n    app = Flask(import_name)\nexcept RuntimeError:\n    app = Flask(import_name, root_path=os.path.dirname(__file__))","preventionTips":["Ensure packages have __init__.py so they are not namespace packages.","Pass root_path explicitly when the import name is dynamic or synthetic."],"tags":["flask","packaging","namespace-package","configuration"],"backgroundTag":null,"analyzedSha":"3596b1ab61cea85edb8970e83ff61daa073facf8","analyzedAt":"2026-08-11T20:11:52.622Z","contentChangedAt":null,"schemaVersion":2},"datasetVersion":"2026-09-23T08:17:48.524Z"}