Python 3.2+Exceptionsexception

ResourceWarning

built-in exceptions

A resource was not released (e.g. an unclosed file; hidden by default).

Syntax

raise ResourceWarning

The default warning filters silence it, so an unclosed file usually leaves no trace — run with python -X dev or -W default when you suspect leaking descriptors. It fires whenever the garbage collector finally reaches the object, so the reported location rarely matches where the file was opened. The fix is a with block, never an except.

Examples

try:
    raise ResourceWarning
except ResourceWarning as e:
    print(type(e).__name__)   # → ResourceWarning

See also

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