安裝 Python 模組(舊版)¶
- 作者
Greg Ward
備註
整个 distutils
包已被弃用并将在 Python 3.12 中被移除。 此文档仅保留作参考,并将随包一起被移除。 更多信息请参阅 有什么新变化 条目。
也參考
- 安裝 Python 模組
最新的模块安装文档。对于常规Python使用,你几乎肯定像使用该文档而非这个。
備註
这篇文档是历史遗留文档,在 https://setuptools.readthedocs.io/en/latest/setuptools.html 上的 setuptools
文档独立涵盖此处包含的所有相关信息之后,将不再单独作为正式文档保留。
備註
本指南仅介绍构建和分发扩展的基本工具,这些扩展是作为此Python版本的一部分提供的。 第三方工具提供更易于使用和更安全的替代方案。有关详细信息,请参阅 Python 打包用户指南中的 快速推荐部分 。
簡介¶
在Python 2.0中,distutils
API 首次被添加到标准库中。这向Linux发行版维护者提供了一个将Python项目转换为发行版软件包的标准方法,以及向系统管理员们提供了直接将这些软件包安装到目标系统的标准方法。
自从很多年前 Python 2.0 发布,将构建系统和包安装器与语言运行时的释放循环紧密连接在一起产生了很多问题。现在推荐做法是在项目中使用 pip
包安装器和 setuptools
构建系统,而不是直接使用 distutils
。
请参阅 安裝 Python 模組 和 發布 Python 模組 了解更多细节。
这个旧文档将被保留,至到我们相信 setuptools
覆盖了所有内容。
基于 distutils
的源代码分发¶
如果你下载了一个模块源代码发布包,你可以很快地确定它是否按标准方式,即使用 Distutils 进行打包和分发。 首先,发布包的名称和版本号将在已下载归档文件的名称中明确显示,例如 foo-1.0.tar.gz
或 widget-0.9.7.zip
。 然后,归档文件将被解包为类似名称的目录: foo-1.0
或 widget-0.9.7
。 此外,发布包将包含一个安装脚本 setup.py
,以及一个名为 README.txt
或是 README
的文件,它应当写明构建和安装模块发布包的方式是简单地在终端中运行一条命令:
python setup.py install
Windows 用户应该使用命令提示符来运行命令(
):setup.py install
如果这些事情都属实,那么您已经了解了如何构建和安装您已经下载的模块:只需运行如上的命令。除非您需要以非常规方式安装或者定制构建过程,您其实不需要本文档。更进一步说,以上命令就是您可以从文档中获得的全部。
标准构建及安装¶
正如 基于 distutils 的源代码分发 中所描述的那样,通过 Distutils 构建和安装发行的模块常常只需要在终端执行一个简单的命令。
python setup.py install
平台差异¶
您应当总是在分发文件的根目录处运行设置的命令,比如,模块分发的源代码最高的子目录。例如,如果您刚刚在 Unix 操作系统上下载了一个模块分发的源代码,您需要做的事:
gunzip -c foo-1.0.tar.gz | tar xf - # unpacks into directory foo-1.0
cd foo-1.0
python setup.py install
在 Windows 上,你下载到的可能是 foo-1.0.zip
。 如果你将归档文件下载到 C:\Temp
,则它将被解包至 C:\Temp\foo-1.0
;你可以使用带有图形用户界面的归档管理器(如 WinZip)或命令行工具(如 unzip 或 pkunzip 等)来解包归档文件。 然后,打开一个命令行提示符窗口并运行:
cd c:\Temp\foo-1.0
python setup.py install
拆分任务¶
Running setup.py install
builds and installs all modules in one run. If you
prefer to work incrementally---especially useful if you want to customize the
build process, or if things are going wrong---you can use the setup script to do
one thing at a time. This is particularly helpful when the build and install
will be done by different users---for example, you might want to build a module
distribution and hand it off to a system administrator for installation (or do
it yourself, with super-user privileges).
For example, you can build everything in one step, and then install everything in a second step, by invoking the setup script twice:
python setup.py build
python setup.py install
If you do this, you will notice that running the install command
first runs the build command, which---in this case---quickly notices
that it has nothing to do, since everything in the build
directory is
up-to-date.
You may not need this ability to break things down often if all you do is install modules downloaded off the 'net, but it's very handy for more advanced tasks. If you get into distributing your own Python modules and extensions, you'll run lots of individual Distutils commands on their own.
How building works¶
As implied above, the build command is responsible for putting the
files to install into a build directory. By default, this is build
under the distribution root; if you're excessively concerned with speed, or want
to keep the source tree pristine, you can change the build directory with the
--build-base
option. For example:
python setup.py build --build-base=/path/to/pybuild/foo-1.0
(Or you could do this permanently with a directive in your system or personal Distutils configuration file; see section Distutils 配置文件Configuration Files.) Normally, this isn't necessary.
The default layout for the build tree is as follows:
--- build/ --- lib/
or
--- build/ --- lib.<plat>/
temp.<plat>/
where <plat>
expands to a brief description of the current OS/hardware
platform and Python version. The first form, with just a lib
directory,
is used for "pure module distributions"---that is, module distributions that
include only pure Python modules. If a module distribution contains any
extensions (modules written in C/C++), then the second form, with two <plat>
directories, is used. In that case, the temp.plat
directory holds
temporary files generated by the compile/link process that don't actually get
installed. In either case, the lib
(or lib.plat
) directory
contains all Python modules (pure Python and extensions) that will be installed.
In the future, more directories will be added to handle Python scripts, documentation, binary executables, and whatever else is needed to handle the job of installing Python modules and applications.
How installation works¶
After the build command runs (whether you run it explicitly, or the
install command does it for you), the work of the install
command is relatively simple: all it has to do is copy everything under
build/lib
(or build/lib.plat
) to your chosen installation
directory.
If you don't choose an installation directory---i.e., if you just run setup.py
install
---then the install command installs to the standard
location for third-party Python modules. This location varies by platform and
by how you built/installed Python itself. On Unix (and macOS, which is also
Unix-based), it also depends on whether the module distribution being installed
is pure Python or contains extensions ("non-pure"):
平台 |
标准安装位置 |
默认值 |
註解 |
---|---|---|---|
(单一)Unix |
|
|
(1) |
(类)Unix |
|
|
(1) |
Windows |
|
|
(2) |
註解:
Most Linux distributions include Python as a standard part of the system, so
prefix
andexec-prefix
are usually both/usr
on Linux. If you build Python yourself on Linux (or any Unix-like system), the defaultprefix
andexec-prefix
are/usr/local
.The default installation directory on Windows was
C:\Program Files\Python
under Python 1.6a1, 1.5.2, and earlier.
prefix
and exec-prefix
stand for the directories that Python
is installed to, and where it finds its libraries at run-time. They are always
the same under Windows, and very often the same under Unix and macOS. You
can find out what your Python installation uses for prefix
and
exec-prefix
by running Python in interactive mode and typing a few
simple commands. Under Unix, just type python
at the shell prompt. Under
Windows, choose . Once the interpreter is started, you type Python code
at the prompt. For example, on my Linux system, I type the three Python
statements shown below, and get the output as shown, to find out my
prefix
and exec-prefix
:
Python 2.4 (#26, Aug 7 2004, 17:19:02)
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys
>>> sys.prefix
'/usr'
>>> sys.exec_prefix
'/usr'
A few other placeholders are used in this document: X.Y
stands for the
version of Python, for example 3.2
; abiflags
will be replaced by
the value of sys.abiflags
or the empty string for platforms which don't
define ABI flags; distname
will be replaced by the name of the module
distribution being installed. Dots and capitalization are important in the
paths; for example, a value that uses python3.2
on UNIX will typically use
Python32
on Windows.
If you don't want to install modules to the standard location, or if you don't have permission to write there, then you need to read about alternate installations in section 可选安装形式. If you want to customize your installation directories more heavily, see section 自定义安装 on custom installations.
可选安装形式¶
Often, it is necessary or desirable to install modules to a location other than the standard location for third-party Python modules. For example, on a Unix system you might not have permission to write to the standard third-party module directory. Or you might wish to try out a module before making it a standard part of your local Python installation. This is especially true when upgrading a distribution already present: you want to make sure your existing base of scripts still works with the new version before actually upgrading.
The Distutils install command is designed to make installing module distributions to an alternate location simple and painless. The basic idea is that you supply a base directory for the installation, and the install command picks a set of directories (called an installation scheme) under this base directory in which to install files. The details differ across platforms, so read whichever of the following sections applies to you.
Note that the various alternate installation schemes are mutually exclusive: you
can pass --user
, or --home
, or --prefix
and --exec-prefix
, or
--install-base
and --install-platbase
, but you can't mix from these
groups.
可选安装形式:用户方案¶
此方案被设计为针对没有全局 site-packages 目录写入权限或不想安装到该目录的用户的最便捷解决方案。 它可以通过一个简单的选项来启用:
python setup.py install --user
Files will be installed into subdirectories of site.USER_BASE
(written
as userbase
hereafter). This scheme installs pure Python modules and
extension modules in the same location (also known as site.USER_SITE
).
Here are the values for UNIX, including macOS:
文件类型 |
安装目录 |
---|---|
模組 |
|
脚本 |
|
数据 |
|
C 头文件 |
|
以下是Windows上使用的值:
文件类型 |
安装目录 |
---|---|
模組 |
|
脚本 |
|
数据 |
|
C 头文件 |
|
The advantage of using this scheme compared to the other ones described below is
that the user site-packages directory is under normal conditions always included
in sys.path
(see site
for more information), which means that
there is no additional step to perform after running the setup.py
script
to finalize the installation.
The build_ext command also has a --user
option to add
userbase/include
to the compiler search path for header files and
userbase/lib
to the compiler search path for libraries as well as to
the runtime search path for shared C libraries (rpath).
可选安装形式:家目录方案¶
“主方案”背后的理念是你可以构建并维护个人的 Python 模块集。 该方案的名称源自 Unix 上“主目录”的概念,因为通常 Unix 用户会将其主目录的布局设置为与 /usr/
或 /usr/local/
相似。 任何人都可以使用该方案,无论其安装的操作系统是什么。
Installing a new module distribution is as simple as
python setup.py install --home=<dir>
where you can supply any directory you like for the --home
option. On
Unix, lazy typists can just type a tilde (~
); the install command
will expand this to your home directory:
python setup.py install --home=~
To make Python find the distributions installed with this scheme, you may have
to modify Python's search path or edit
sitecustomize
(see site
) to call site.addsitedir()
or edit
sys.path
.
The --home
option defines the installation base directory. Files are
installed to the following directories under the installation base as follows:
文件类型 |
安装目录 |
---|---|
模組 |
|
脚本 |
|
数据 |
|
C 头文件 |
|
(如果你是使用 Windows 请将斜杠替换为反斜杠。)
可选安装形式:Unix(前缀方案)¶
“前缀方案”适用于当你希望使用一个 Python 安装程序来执行构建/安装(即运行 setup 脚本),但需要将模块安装到另一个 Python 安装版(或看起来类似于另一个 Python 安装版)的第三方模块目录中的情况。 如果这听起来有点不寻常,确实如此 --- 这就是为什么要先介绍用户和主目录方案的原因。 然而,至少有两种已知的情况会用到前缀方案。
First, consider that many Linux distributions put Python in /usr
, rather
than the more traditional /usr/local
. This is entirely appropriate,
since in those cases Python is part of "the system" rather than a local add-on.
However, if you are installing Python modules from source, you probably want
them to go in /usr/local/lib/python2.X
rather than
/usr/lib/python2.X
. This can be done with
/usr/bin/python setup.py install --prefix=/usr/local
Another possibility is a network filesystem where the name used to write to a
remote directory is different from the name used to read it: for example, the
Python interpreter accessed as /usr/local/bin/python
might search for
modules in /usr/local/lib/python2.X
, but those modules would have to
be installed to, say, /mnt/@server/export/lib/python2.X
. This could
be done with
/usr/local/bin/python setup.py install --prefix=/mnt/@server/export
In either case, the --prefix
option defines the installation base, and
the --exec-prefix
option defines the platform-specific installation
base, which is used for platform-specific files. (Currently, this just means
non-pure module distributions, but could be expanded to C libraries, binary
executables, etc.) If --exec-prefix
is not supplied, it defaults to
--prefix
. Files are installed as follows:
文件类型 |
安装目录 |
---|---|
Python 模块 |
|
扩展模块 |
|
脚本 |
|
数据 |
|
C 头文件 |
|
There is no requirement that --prefix
or --exec-prefix
actually point to an alternate Python installation; if the directories listed
above do not already exist, they are created at installation time.
Incidentally, the real reason the prefix scheme is important is simply that a
standard Unix installation uses the prefix scheme, but with --prefix
and --exec-prefix
supplied by Python itself as sys.prefix
and
sys.exec_prefix
. Thus, you might think you'll never use the prefix scheme,
but every time you run python setup.py install
without any other options,
you're using it.
Note that installing extensions to an alternate Python installation has no
effect on how those extensions are built: in particular, the Python header files
(Python.h
and friends) installed with the Python interpreter used to run
the setup script will be used in compiling extensions. It is your
responsibility to ensure that the interpreter used to run extensions installed
in this way is compatible with the interpreter used to build them. The best way
to do this is to ensure that the two interpreters are the same version of Python
(possibly different builds, or possibly copies of the same build). (Of course,
if your --prefix
and --exec-prefix
don't even point to an
alternate Python installation, this is immaterial.)
Alternate installation: Windows (the prefix scheme)¶
Windows has no concept of a user's home directory, and since the standard Python
installation under Windows is simpler than under Unix, the --prefix
option has traditionally been used to install additional packages in separate
locations on Windows.
python setup.py install --prefix="\Temp\Python"
to install modules to the \Temp\Python
directory on the current drive.
The installation base is defined by the --prefix
option; the
--exec-prefix
option is not supported under Windows, which means that
pure Python modules and extension modules are installed into the same location.
Files are installed as follows:
文件类型 |
安装目录 |
---|---|
模組 |
|
脚本 |
|
数据 |
|
C 头文件 |
|
自定义安装¶
Sometimes, the alternate installation schemes described in section 可选安装形式 just don't do what you want. You might want to tweak just one or two directories while keeping everything under the same base directory, or you might want to completely redefine the installation scheme. In either case, you're creating a custom installation scheme.
To create a custom installation scheme, you start with one of the alternate schemes and override some of the installation directories used for the various types of files, using these options:
文件类型 |
覆盖选项 |
---|---|
Python 模块 |
|
扩展模块 |
|
所有模块 |
|
脚本 |
|
数据 |
|
C 头文件 |
|
These override options can be relative, absolute,
or explicitly defined in terms of one of the installation base directories.
(There are two installation base directories, and they are normally the
same---they only differ when you use the Unix "prefix scheme" and supply
different --prefix
and --exec-prefix
options; using --install-lib
will override values computed or given for --install-purelib
and
--install-platlib
, and is recommended for schemes that don't make a
difference between Python and extension modules.)
For example, say you're installing a module distribution to your home directory
under Unix---but you want scripts to go in ~/scripts
rather than
~/bin
. As you might expect, you can override this directory with the
--install-scripts
option; in this case, it makes most sense to supply
a relative path, which will be interpreted relative to the installation base
directory (your home directory, in this case):
python setup.py install --home=~ --install-scripts=scripts
Another Unix example: suppose your Python installation was built and installed
with a prefix of /usr/local/python
, so under a standard installation
scripts will wind up in /usr/local/python/bin
. If you want them in
/usr/local/bin
instead, you would supply this absolute directory for the
--install-scripts
option:
python setup.py install --install-scripts=/usr/local/bin
(This performs an installation using the "prefix scheme", where the prefix is
whatever your Python interpreter was installed with--- /usr/local/python
in this case.)
If you maintain Python on Windows, you might want third-party modules to live in
a subdirectory of prefix
, rather than right in prefix
itself. This is almost as easy as customizing the script installation
directory---you just have to remember that there are two types of modules
to worry about, Python and extension modules, which can conveniently be both
controlled by one option:
python setup.py install --install-lib=Site
The specified installation directory is relative to prefix
. Of
course, you also have to ensure that this directory is in Python's module
search path, such as by putting a .pth
file in a site directory (see
site
). See section 修改 Python 的搜索路径 to find out how to modify
Python's search path.
If you want to define an entire installation scheme, you just have to supply all
of the installation directory options. The recommended way to do this is to
supply relative paths; for example, if you want to maintain all Python
module-related files under python
in your home directory, and you want a
separate directory for each platform that you use your home directory from, you
might define the following installation scheme:
python setup.py install --home=~ \
--install-purelib=python/lib \
--install-platlib=python/lib.$PLAT \
--install-scripts=python/scripts
--install-data=python/data
或者,等价于
python setup.py install --home=~/python \
--install-purelib=lib \
--install-platlib='lib.$PLAT' \
--install-scripts=scripts
--install-data=data
$PLAT
is not (necessarily) an environment variable---it will be expanded by
the Distutils as it parses your command line options, just as it does when
parsing your configuration file(s).
Obviously, specifying the entire installation scheme every time you install a new module distribution would be very tedious. Thus, you can put these options into your Distutils config file (see section Distutils 配置文件Configuration Files):
[install]
install-base=$HOME
install-purelib=python/lib
install-platlib=python/lib.$PLAT
install-scripts=python/scripts
install-data=python/data
或者,等价于,
[install]
install-base=$HOME/python
install-purelib=lib
install-platlib=lib.$PLAT
install-scripts=scripts
install-data=data
Note that these two are not equivalent if you supply a different installation base directory when you run the setup script. For example,
python setup.py install --install-base=/tmp
would install pure modules to /tmp/python/lib
in the first case, and
to /tmp/lib
in the second case. (For the second case, you probably
want to supply an installation base of /tmp/python
.)
You probably noticed the use of $HOME
and $PLAT
in the sample
configuration file input. These are Distutils configuration variables, which
bear a strong resemblance to environment variables. In fact, you can use
environment variables in config files on platforms that have such a notion but
the Distutils additionally define a few extra variables that may not be in your
environment, such as $PLAT
. (And of course, on systems that don't have
environment variables, such as Mac OS 9, the configuration variables supplied by
the Distutils are the only ones you can use.) See section Distutils 配置文件Configuration Files
for details.
備註
When a virtual environment is activated, any options that change the installation path will be ignored from all distutils configuration files to prevent inadvertently installing projects outside of the virtual environment.
修改 Python 的搜索路径¶
When the Python interpreter executes an import
statement, it searches
for both Python code and extension modules along a search path. A default value
for the path is configured into the Python binary when the interpreter is built.
You can determine the path by importing the sys
module and printing the
value of sys.path
.
$ python
Python 2.2 (#11, Oct 3 2002, 13:31:27)
[GCC 2.96 20000731 (Red Hat Linux 7.3 2.96-112)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys
>>> sys.path
['', '/usr/local/lib/python2.3', '/usr/local/lib/python2.3/plat-linux2',
'/usr/local/lib/python2.3/lib-tk', '/usr/local/lib/python2.3/lib-dynload',
'/usr/local/lib/python2.3/site-packages']
>>>
The null string in sys.path
represents the current working directory.
The expected convention for locally installed packages is to put them in the
.../site-packages/
directory, but you may want to install Python
modules into some arbitrary directory. For example, your site may have a
convention of keeping all software related to the web server under /www
.
Add-on Python modules might then belong in /www/python
, and in order to
import them, this directory must be added to sys.path
. There are several
different ways to add the directory.
The most convenient way is to add a path configuration file to a directory
that's already on Python's path, usually to the .../site-packages/
directory. Path configuration files have an extension of .pth
, and each
line must contain a single path that will be appended to sys.path
. (Because
the new paths are appended to sys.path
, modules in the added directories
will not override standard modules. This means you can't use this mechanism for
installing fixed versions of standard modules.)
Paths can be absolute or relative, in which case they're relative to the
directory containing the .pth
file. See the documentation of
the site
module for more information.
A slightly less convenient way is to edit the site.py
file in Python's
standard library, and modify sys.path
. site.py
is automatically
imported when the Python interpreter is executed, unless the -S
switch
is supplied to suppress this behaviour. So you could simply edit
site.py
and add two lines to it:
import sys
sys.path.append('/www/python/')
However, if you reinstall the same major version of Python (perhaps when
upgrading from 2.2 to 2.2.2, for example) site.py
will be overwritten by
the stock version. You'd have to remember that it was modified and save a copy
before doing the installation.
There are two environment variables that can modify sys.path
.
PYTHONHOME
sets an alternate value for the prefix of the Python
installation. For example, if PYTHONHOME
is set to /www/python
,
the search path will be set to ['', '/www/python/lib/pythonX.Y/',
'/www/python/lib/pythonX.Y/plat-linux2', ...]
.
The PYTHONPATH
variable can be set to a list of paths that will be
added to the beginning of sys.path
. For example, if PYTHONPATH
is
set to /www/python:/opt/py
, the search path will begin with
['/www/python', '/opt/py']
. (Note that directories must exist in order to
be added to sys.path
; the site
module removes paths that don't
exist.)
Finally, sys.path
is just a regular Python list, so any Python application
can modify it by adding or removing entries.
Distutils 配置文件Configuration Files¶
As mentioned above, you can use Distutils configuration files to record personal or site preferences for any Distutils options. That is, any option to any command can be stored in one of two or three (depending on your platform) configuration files, which will be consulted before the command-line is parsed. This means that configuration files will override default values, and the command-line will in turn override configuration files. Furthermore, if multiple configuration files apply, values from "earlier" files are overridden by "later" files.
Location and names of config files¶
The names and locations of the configuration files vary slightly across platforms. On Unix and macOS, the three configuration files (in the order they are processed) are:
文件类型 |
位置和文件名 |
註解 |
---|---|---|
system |
|
(1) |
personal |
|
(2) |
local |
|
(3) |
而在 Windows 中,配置文件为:
文件类型 |
位置和文件名 |
註解 |
---|---|---|
system |
|
(4) |
personal |
|
(5) |
local |
|
(3) |
On all platforms, the "personal" file can be temporarily disabled by
passing the --no-user-cfg
option.
註解:
Strictly speaking, the system-wide configuration file lives in the directory where the Distutils are installed; under Python 1.6 and later on Unix, this is as shown. For Python 1.5.2, the Distutils will normally be installed to
prefix/lib/python1.5/site-packages/distutils
, so the system configuration file should be put there under Python 1.5.2.On Unix, if the
HOME
environment variable is not defined, the user's home directory will be determined with thegetpwuid()
function from the standardpwd
module. This is done by theos.path.expanduser()
function used by Distutils.I.e., in the current directory (usually the location of the setup script).
(See also note (1).) Under Python 1.6 and later, Python's default "installation prefix" is
C:\Python
, so the system configuration file is normallyC:\Python\Lib\distutils\distutils.cfg
. Under Python 1.5.2, the default prefix wasC:\Program Files\Python
, and the Distutils were not part of the standard library---so the system configuration file would beC:\Program Files\Python\distutils\distutils.cfg
in a standard Python 1.5.2 installation under Windows.On Windows, if the
HOME
environment variable is not defined,USERPROFILE
thenHOMEDRIVE
andHOMEPATH
will be tried. This is done by theos.path.expanduser()
function used by Distutils.
Syntax of config files¶
The Distutils configuration files all have the same syntax. The config files
are grouped into sections. There is one section for each Distutils command,
plus a global
section for global options that affect every command. Each
section consists of one option per line, specified as option=value
.
For example, the following is a complete config file that just forces all commands to run quietly by default:
[global]
verbose=0
If this is installed as the system config file, it will affect all processing of
any Python module distribution by any user on the current system. If it is
installed as your personal config file (on systems that support them), it will
affect only module distributions processed by you. And if it is used as the
setup.cfg
for a particular module distribution, it affects only that
distribution.
You could override the default "build base" directory and make the build* commands always forcibly rebuild all files with the following:
[build]
build-base=blib
force=1
which corresponds to the command-line arguments
python setup.py build --build-base=blib --force
except that including the build command on the command-line means that command will be run. Including a particular command in config files has no such implication; it only means that if the command is run, the options in the config file will apply. (Or if other commands that derive values from it are run, they will use the values in the config file.)
You can find out the complete list of options for any command using the
--help
option, e.g.:
python setup.py build --help
and you can find out the complete list of global options by using
--help
without a command:
python setup.py --help
See also the "Reference" section of the "Distributing Python Modules" manual.
Building Extensions: Tips and Tricks¶
Whenever possible, the Distutils try to use the configuration information made
available by the Python interpreter used to run the setup.py
script.
For example, the same compiler and linker flags used to compile Python will also
be used for compiling extensions. Usually this will work well, but in
complicated situations this might be inappropriate. This section discusses how
to override the usual Distutils behaviour.
Tweaking compiler/linker flags¶
Compiling a Python extension written in C or C++ will sometimes require specifying custom flags for the compiler and linker in order to use a particular library or produce a special kind of object code. This is especially true if the extension hasn't been tested on your platform, or if you're trying to cross-compile Python.
In the most general case, the extension author might have foreseen that
compiling the extensions would be complicated, and provided a Setup
file
for you to edit. This will likely only be done if the module distribution
contains many separate extension modules, or if they often require elaborate
sets of compiler flags in order to work.
A Setup
file, if present, is parsed in order to get a list of extensions
to build. Each line in a Setup
describes a single module. Lines have
the following structure:
module ... [sourcefile ...] [cpparg ...] [library ...]
Let's examine each of the fields in turn.
module is the name of the extension module to be built, and should be a valid Python identifier. You can't just change this in order to rename a module (edits to the source code would also be needed), so this should be left alone.
sourcefile is anything that's likely to be a source code file, at least judging by the filename. Filenames ending in
.c
are assumed to be written in C, filenames ending in.C
,.cc
, and.c++
are assumed to be C++, and filenames ending in.m
or.mm
are assumed to be in Objective C.cpparg is an argument for the C preprocessor, and is anything starting with
-I
,-D
,-U
or-C
.library is anything ending in
.a
or beginning with-l
or-L
.
If a particular platform requires a special library on your platform, you can
add it by editing the Setup
file and running python setup.py build
.
For example, if the module defined by the line
foo foomodule.c
must be linked with the math library libm.a
on your platform, simply add
-lm
to the line:
foo foomodule.c -lm
Arbitrary switches intended for the compiler or the linker can be supplied with
the -Xcompiler
arg and -Xlinker
arg options:
foo foomodule.c -Xcompiler -o32 -Xlinker -shared -lm
The next option after -Xcompiler
and -Xlinker
will be
appended to the proper command line, so in the above example the compiler will
be passed the -o32
option, and the linker will be passed
-shared
. If a compiler option requires an argument, you'll have to
supply multiple -Xcompiler
options; for example, to pass -x c++
the Setup
file would have to contain -Xcompiler -x -Xcompiler c++
.
Compiler flags can also be supplied through setting the CFLAGS
environment variable. If set, the contents of CFLAGS
will be added to
the compiler flags specified in the Setup
file.
在 Windows 上使用非 Microsoft 编辑器¶
Borland/CodeGear C++¶
This subsection describes the necessary steps to use Distutils with the Borland
C++ compiler version 5.5. First you have to know that Borland's object file
format (OMF) is different from the format used by the Python version you can
download from the Python or ActiveState web site. (Python is built with
Microsoft Visual C++, which uses COFF as the object file format.) For this
reason you have to convert Python's library python25.lib
into the
Borland format. You can do this as follows:
coff2omf python25.lib python25_bcpp.lib
The coff2omf
program comes with the Borland compiler. The file
python25.lib
is in the Libs
directory of your Python
installation. If your extension uses other libraries (zlib, ...) you have to
convert them too.
The converted files have to reside in the same directories as the normal libraries.
How does Distutils manage to use these libraries with their changed names? If
the extension needs a library (eg. foo
) Distutils checks first if it
finds a library with suffix _bcpp
(eg. foo_bcpp.lib
) and then
uses this library. In the case it doesn't find such a special library it uses
the default name (foo.lib
.) 1
To let Distutils compile your extension with Borland C++ you now have to type:
python setup.py build --compiler=bcpp
If you want to use the Borland C++ compiler as the default, you could specify this in your personal or system-wide configuration file for Distutils (see section Distutils 配置文件Configuration Files.)
也參考
- C++Builder Compiler
有关 Borland 发布的免费 C++ 编译器的信息,包括下载页面的链接。
- Creating Python Extensions Using Borland's Free Compiler
介绍如何使用 Borland 发布的免费命令行方式 C++ 编译器构建 Python 的文档。
GNU C / Cygwin / MinGW¶
This section describes the necessary steps to use Distutils with the GNU C/C++ compilers in their Cygwin and MinGW distributions. 2 For a Python interpreter that was built with Cygwin, everything should work without any of these following steps.
Not all extensions can be built with MinGW or Cygwin, but many can. Extensions most likely to not work are those that use C++ or depend on Microsoft Visual C extensions.
To let Distutils compile your extension with Cygwin you have to type:
python setup.py build --compiler=cygwin
and for Cygwin in no-cygwin mode 3 or for MinGW type:
python setup.py build --compiler=mingw32
If you want to use any of these options/compilers as default, you should consider writing it in your personal or system-wide configuration file for Distutils (see section Distutils 配置文件Configuration Files.)
旧版 Python 和 MinGW¶
The following instructions only apply if you're using a version of Python inferior to 2.4.1 with a MinGW inferior to 3.0.0 (with binutils-2.13.90-20030111-1).
These compilers require some special libraries. This task is more complex than for Borland's C++, because there is no program to convert the library. First you have to create a list of symbols which the Python DLL exports. (You can find a good program for this task at https://sourceforge.net/projects/mingw/files/MinGW/Extension/pexports/).
pexports python25.dll >python25.def
The location of an installed python25.dll
will depend on the
installation options and the version and language of Windows. In a "just for
me" installation, it will appear in the root of the installation directory. In
a shared installation, it will be located in the system directory.
Then you can create from these information an import library for gcc.
/cygwin/bin/dlltool --dllname python25.dll --def python25.def --output-lib libpython25.a
The resulting library has to be placed in the same directory as
python25.lib
. (Should be the libs
directory under your Python
installation directory.)
If your extension uses other libraries (zlib,...) you might have to convert them too. The converted files have to reside in the same directories as the normal libraries do.
也參考
- 在 MS Windows 平台上使用 MinGW 构建 Python 模块
针对 MinGW 环境生成必要的库的相关信息
註解