Function _find_and_load

Lib/importlib/_bootstrap.py:1271–1302

Find and load the module.

(name, import_)

def _find_and_load(name, import_):
    """Find and load the module."""

    # Optimization: we avoid unneeded module locking if the module
    # already exists in sys.modules and is fully initialized.
    module = sys.modules.get(name, _NEEDS_LOADING)
    if (module is _NEEDS_LOADING or
        getattr(getattr(module, "__spec__", None), "_initializing", False)):
        with _ModuleLockManager(name):
            module = sys.modules.get(name, _NEEDS_LOADING)
            if module is _NEEDS_LOADING:
                return _find_and_load_unlocked(name, import_)

        # Optimization: only call _bootstrap._lock_unlock_module() if
        # module.__spec__._initializing is True.
        # NOTE: because of this, initializing must be set *before*
        # putting the new module in sys.modules.
        _lock_unlock_module(name)
    else:
        # Verify the module is still in sys.modules. Another thread may have
        # removed it (due to import failure) between our sys.modules.get()
        # above and the _initializing check. If removed, we retry the import
        # to preserve normal semantics: the caller gets the exception from
        # the actual import failure rather than a synthetic error.
        if sys.modules.get(name) is not module:
            return _find_and_load(name, import_)

    if module is None:
        message = f'import of {name} halted; None in sys.modules'
        raise ModuleNotFoundError(message, name=name)

    return module


def _gcd_import(name, package=None, level=0):