all Python 3ctypesterm

ctypes

module

Calling functions in C libraries and working with C types directly from Python.

Syntax

import ctypes

Use it to call an existing C library (DLL, .so) without writing an extension: load it with CDLL, declare argument types and call it. Large bindings are easier with cffi or C extensions, and packing numbers into bytes only needs struct. A wrong argument type is not caught by any check and can crash the whole interpreter; the module is optional and may be missing from a build.

Examples

import importlib.util
if importlib.util.find_spec('ctypes') is not None:
    import ctypes
    n = ctypes.c_int(41)
    n.value += 1
    print(n.value)  # → ? 42, если ctypes есть в сборке

See also

Common errors

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