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| -rw-r--r-- | Doc/c-api/arg.rst | 22 |
1 files changed, 14 insertions, 8 deletions
diff --git a/Doc/c-api/arg.rst b/Doc/c-api/arg.rst index 3201bdc..41c0366 100644 --- a/Doc/c-api/arg.rst +++ b/Doc/c-api/arg.rst @@ -229,12 +229,24 @@ There are three ways strings and buffers can be converted to C: Numbers ------- +These formats allow representing Python numbers or single characters as C numbers. +Formats that require :class:`int`, :class:`float` or :class:`complex` can +also use the corresponding special methods :meth:`~object.__index__`, +:meth:`~object.__float__` or :meth:`~object.__complex__` to convert +the Python object to the required type. + +For signed integer formats, :exc:`OverflowError` is raised if the value +is out of range for the C type. +For unsigned integer formats, no range checking is done --- the +most significant bits are silently truncated when the receiving field is too +small to receive the value. + ``b`` (:class:`int`) [unsigned char] - Convert a nonnegative Python integer to an unsigned tiny int, stored in a C + Convert a nonnegative Python integer to an unsigned tiny integer, stored in a C :c:expr:`unsigned char`. ``B`` (:class:`int`) [unsigned char] - Convert a Python integer to a tiny int without overflow checking, stored in a C + Convert a Python integer to a tiny integer without overflow checking, stored in a C :c:expr:`unsigned char`. ``h`` (:class:`int`) [short int] @@ -344,12 +356,6 @@ Other objects in *items*. The C arguments must correspond to the individual format units in *items*. Format units for sequences may be nested. -It is possible to pass "long" integers (integers whose value exceeds the -platform's :c:macro:`LONG_MAX`) however no proper range checking is done --- the -most significant bits are silently truncated when the receiving field is too -small to receive the value (actually, the semantics are inherited from downcasts -in C --- your mileage may vary). - A few other characters have a meaning in a format string. These may not occur inside nested parentheses. They are: |