autoreload.py 文件源码

def _reload_on_update(modify_times):
    if _reload_attempted:
        # We already tried to reload and it didn't work, so don't try again.
        return
    if process.task_id() is not None:
        # We're in a child process created by fork_processes.  If child
        # processes restarted themselves, they'd all restart and then
        # all call fork_processes again.
        return
    for module in list(sys.modules.values()):
        # Some modules play games with sys.modules (e.g. email/__init__.py
        # in the standard library), and occasionally this can cause strange
        # failures in getattr.  Just ignore anything that's not an ordinary
        # module.
        if not isinstance(module, types.ModuleType):
            continue
        path = getattr(module, "__file__", None)
        if not path:
            continue
        if path.endswith(".pyc") or path.endswith(".pyo"):
            path = path[:-1]
        _check_file(modify_times, path)
    for path in _watched_files:
        _check_file(modify_times, path)