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Exceptions

proxylib.exceptions

The exceptions proxylib raises.

Every library error derives from :class:ProxylibError. None of them derives from KeyError: a proxy map raises KeyError to mean "no opinion, ask the next map", and an error must never be mistaken for that.

__all__ = ('ProxylibError', 'ProxyParseError', 'PACError', 'NoReachableProxyError', 'MissingExtraError', 'UnsupportedProxyError') module-attribute

MissingExtraError(feature, *, name, extra=None)

Bases: ProxylibError, ImportError

An optional dependency is not installed.

extra is the proxylib extra that installs it, or None when the dependency is a client library proxylib integrates with and has no extra for (requests); name is the module that failed to import. The message names the pip install line.

Source code in src/proxylib/exceptions.py 
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def __init__(self, feature: str, *, name: str, extra: "Optional[str]" = None) -> None:
    self.feature = feature
    self.extra = extra
    target = f'"proxylib[{extra}]"' if extra else name
    super().__init__(f"{feature} needs {name}: pip install {target}", name=name)

extra = extra instance-attribute

feature = feature instance-attribute

NoReachableProxyError

Bases: ProxylibError, LookupError

None of the proxies offered for a request accepted a connection.

PACError

Bases: ProxylibError

A PAC script failed: it raised, returned no usable answer in time, or could not be loaded as a script.

ProxyParseError

Bases: ProxylibError, ValueError

Text that should name a proxy, or a PAC result, could not be parsed.

ProxylibError

Bases: Exception

Base class of every error proxylib raises.

UnsupportedProxyError(client, refused)

Bases: ProxylibError

A client was offered only proxies it cannot use: a URL-prefix gateway or a SOCKS proxy for a client without them, or a proxy header the client cannot keep from the server. Entries it can use are tried instead when the answer has any.

client names the client; proxies are the entries offered, and reasons says why each was refused.

Source code in src/proxylib/exceptions.py 
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def __init__(self, client: str, refused: "Iterable[Tuple[Any, str]]") -> None:
    refused = tuple(refused)
    self.client = client
    self.proxies = tuple(proxy for proxy, _ in refused)
    self.reasons = tuple(reason for _, reason in refused)
    detail = "; ".join(f"{proxy.url} ({reason})" for proxy, reason in refused)
    super().__init__(f"{client} cannot use any proxy offered: {detail}")

client = client instance-attribute

proxies = tuple(proxy for proxy, _ in refused) instance-attribute

reasons = tuple(reason for _, reason in refused) instance-attribute