diff options
Diffstat (limited to 'Doc/faq')
| -rw-r--r-- | Doc/faq/design.rst | 2 | ||||
| -rw-r--r-- | Doc/faq/extending.rst | 31 |
2 files changed, 1 insertions, 32 deletions
diff --git a/Doc/faq/design.rst b/Doc/faq/design.rst index 02417b1..1f3135a 100644 --- a/Doc/faq/design.rst +++ b/Doc/faq/design.rst @@ -667,7 +667,7 @@ construction of large programs. Python 2.6 adds an :mod:`abc` module that lets you define Abstract Base Classes (ABCs). You can then use :func:`isinstance` and :func:`issubclass` to check whether an instance or a class implements a particular ABC. The -:mod:`collections` module defines a set of useful ABCs such as +:mod:`collections.abc` module defines a set of useful ABCs such as :class:`Iterable`, :class:`Container`, and :class:`MutableMapping`. For Python, many of the advantages of interface specifications can be obtained diff --git a/Doc/faq/extending.rst b/Doc/faq/extending.rst index fa8e6e7..bbc322a 100644 --- a/Doc/faq/extending.rst +++ b/Doc/faq/extending.rst @@ -447,34 +447,3 @@ In Python 2.2, you can inherit from built-in classes such as :class:`int`, The Boost Python Library (BPL, http://www.boost.org/libs/python/doc/index.html) provides a way of doing this from C++ (i.e. you can inherit from an extension class written in C++ using the BPL). - - -When importing module X, why do I get "undefined symbol: PyUnicodeUCS2*"? -------------------------------------------------------------------------- - -You are using a version of Python that uses a 4-byte representation for Unicode -characters, but some C extension module you are importing was compiled using a -Python that uses a 2-byte representation for Unicode characters (the default). - -If instead the name of the undefined symbol starts with ``PyUnicodeUCS4``, the -problem is the reverse: Python was built using 2-byte Unicode characters, and -the extension module was compiled using a Python with 4-byte Unicode characters. - -This can easily occur when using pre-built extension packages. RedHat Linux -7.x, in particular, provided a "python2" binary that is compiled with 4-byte -Unicode. This only causes the link failure if the extension uses any of the -``PyUnicode_*()`` functions. It is also a problem if an extension uses any of -the Unicode-related format specifiers for :c:func:`Py_BuildValue` (or similar) or -parameter specifications for :c:func:`PyArg_ParseTuple`. - -You can check the size of the Unicode character a Python interpreter is using by -checking the value of sys.maxunicode: - - >>> import sys - >>> if sys.maxunicode > 65535: - ... print('UCS4 build') - ... else: - ... print('UCS2 build') - -The only way to solve this problem is to use extension modules compiled with a -Python binary built using the same size for Unicode characters. |