all Python 3ctypesexception

ctypes.ArgumentError

exceptions

A ctypes exception raised when a foreign function call cannot convert one of the passed arguments; it inherits directly from Exception, not from TypeError.

Syntax

ctypes.ArgumentError

The surprise is that it inherits straight from Exception, so an except TypeError around your foreign call will not catch it — name ctypes.ArgumentError explicitly. It fires while converting one specific argument, and the message tells you which position failed, so read it instead of guessing. The flip side: with no argtypes declared there is nothing to check, and instead of a clean ArgumentError you risk memory corruption or a hard crash of the process.

Examples

import ctypes
print(issubclass(ctypes.ArgumentError, Exception))  # → True
try:
    raise ctypes.ArgumentError('argument 1: TypeError')
except ctypes.ArgumentError as e:
    print(e)  # → argument 1: TypeError

See also

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