init

2026-02-12 23:22:11 +08:00
parent 7b09eb3d89
commit 89660bba4e
5988 changed files with 2517516 additions and 0 deletions
@@ -0,0 +1,40 @@
+"""
+exceptions.py
+----------------
+
+Wrap exceptions.
+"""
+
+
+class ExceptionWrapper:
+    """
+    Create a dummy object which will raise an exception when attributes
+    are accessed (i.e. when used as a module) or when called (i.e.
+    when used like a function)
+
+    For soft dependencies we want to survive failing to import but
+    we would like to raise an appropriate error when the functionality is
+    actually requested so the user gets an easily debuggable message.
+    """
+
+    def __init__(self, exception: BaseException):
+        # store the exception type and the args rather than the whole thing
+        # this prevents the locals from the time of the exception
+        # from being stored as well.
+        self.exception = (type(exception), exception.args)
+
+    def __getattribute__(self, *args, **kwargs):
+        # will raise when this object is accessed like an object
+        # if it's asking for our class type return None
+        # this allows isinstance() checks to not re-raise
+        if args[0] == "__class__":
+            return None.__class__
+
+        # re-create our original exception from the type and arguments
+        exc_type, exc_args = super().__getattribute__("exception")
+        raise exc_type(*exc_args)
+
+    def __call__(self, *args, **kwargs):
+        # behave the same when this object is called like a function
+        # as when someone tries to access an attribute like a module
+        self.__getattribute__("exception")