"""
Exception classes that may be raised from the Wayback package.
"""
[docs]class WaybackException(Exception):
"Base exception class for all Wayback-specific errors."
[docs]class BlockedByRobotsError(WaybackException):
"""
Raised when a URL can't be queried in Wayback because it was blocked by a
site's `robots.txt` file.
"""
# TODO: split this up into a family of more specific errors? When playback
# failed partway into a redirect chain, when a redirect goes outside
# redirect_target_window, when a memento was circular?
[docs]class MementoPlaybackError(WaybackException):
"""
Raised when a Memento can't be 'played back' (loaded) by the Wayback
Machine for some reason. This is a server-side issue, not a problem in
parsing data from Wayback.
"""
[docs]class WaybackRetryError(WaybackException):
"""
Raised when a request to the Wayback Machine has been retried and failed
too many times. The number of tries before this exception is raised
generally depends on your `WaybackSession` settings.
Attributes
----------
retries : int
The number of retries that were attempted.
cause : Exception
The actual, underlying error that would have caused a retry.
time : int
The total time spent across all retried requests, in seconds.
"""
def __init__(self, retries, total_time, causal_error):
self.retries = retries
self.cause = causal_error
self.time = total_time
super().__init__(f'Retried {retries} times over {total_time or "?"} seconds (error: {causal_error})')
class SessionClosedError(Exception):
"""
Raised when a Wayback session is used to make a request after it has been
closed and disabled.
"""