# 安装Python模块（旧版）

作者

  Greg Ward

参见

安装 Python 模块

  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。

注解

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。

注解

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 。

## 概述

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 安装 Python 模块 和 分发 Python 模块 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

If you download a module source distribution, you can tell pretty quickly if it was packaged and distributed in the standard way, i.e. using the Distutils. First, the distribution's name and version number will be featured prominently in the name of the downloaded archive, e.g. `foo-1.0.tar.gz` or `widget-0.9.7.zip`. Next, the archive will unpack into a similarly-named directory: `foo-1.0` or `widget-0.9.7`. Additionally, the distribution will contain a setup script `setup.py`, and a file named `README.txt` or possibly just `README`, which should explain that building and installing the module distribution is a simple matter of running one command from a terminal:

    python setup.py install

Windows 用户应该使用命令提示符来运行命令(Start ‣ Accessories):

    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 | 备注
--- | --- | --- | ---
（单一）Unix | `prefix/lib/pythonX.Y/site-packages` | `/usr/local/lib/pythonX.Y/site-packages` | (1)
（类）Unix | `exec-prefix/lib/pythonX.Y/site-packages` | `/usr/local/lib/pythonX.Y/site-packages` | (1)
Windows | `prefix\Lib\site-packages` | `C:\PythonXY\Lib\site-packages` | (2)

注释：

1. Most Linux distributions include Python as a standard part of the system, so `prefix` and `exec-prefix` are usually both `/usr` on Linux. If you build Python yourself on Linux (or any Unix-like system), the default `prefix` and `exec-prefix` are `/usr/local`.

2. 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 Start ‣ Programs ‣ Python X.Y ‣ Python (command line). 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
--- | ---
模块 | `userbase/lib/pythonX.Y/site-packages`
脚本 | `userbase/bin`
数据 | `userbase`
C 头文件 | `userbase/include/pythonX.Yabiflags/distname`

以下是Windows上使用的值：

文件类型 | 安装目录
--- | ---
模块 | `userbase\PythonXY\site-packages`
脚本 | `userbase\PythonXY\Scripts`
数据 | `userbase`
C 头文件 | `userbase\PythonXY\Include{distname}`

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
--- | ---
模块 | `home/lib/python`
脚本 | `home/bin`
数据 | `home`
C 头文件 | `home/include/python/distname`

（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 | `prefix/lib/pythonX.Y/site-packages`
扩展模块 | `exec-prefix/lib/pythonX.Y/site-packages`
脚本 | `prefix/bin`
数据 | `prefix`
C 头文件 | `prefix/include/pythonX.Yabiflags/distname`

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
--- | ---
模块 | `prefix\Lib\site-packages`
脚本 | `prefix\Scripts`
数据 | `prefix`
C 头文件 | `prefix\Include{distname}`

## 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 | `--install-purelib`
扩展模块 | `--install-platlib`
所有模块 | `--install-lib`
脚本 | `--install-scripts`
数据 | `--install-data`
C 头文件 | `--install-headers`

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.

注解

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 | 备注
--- | --- | ---
system | `prefix/lib/pythonver/distutils/distutils.cfg` | (1)
personal | `$HOME/.pydistutils.cfg` | (2)
local | `setup.cfg` | (3)

而在 Windows 中，配置文件为:

文件类型 | 位置和文件名 | 备注
--- | --- | ---
system | `prefix\Lib\distutils\distutils.cfg` | (4)
personal | `%HOME%\pydistutils.cfg` | (5)
local | `setup.cfg` | (3)

On all platforms, the "personal" file can be temporarily disabled by passing the --no-user-cfg option.

注释：

1. 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.

2. On Unix, if the `HOME` environment variable is not defined, the user's home directory will be determined with the `getpwuid()` function from the standard `pwd` module. This is done by the `os.path.expanduser()` function used by Distutils.

3. I.e., in the current directory (usually the location of the setup script).

4. (See also note (1).) Under Python 1.6 and later, Python's default "installation prefix" is `C:\Python`, so the system configuration file is normally `C:\Python\Lib\distutils\distutils.cfg`. Under Python 1.5.2, the default prefix was `C:\Program Files\Python`, and the Distutils were not part of the standard library---so the system configuration file would be `C:\Program Files\Python\distutils\distutils.cfg` in a standard Python 1.5.2 installation under Windows.

5. On Windows, if the `HOME` environment variable is not defined, `USERPROFILE` then `HOMEDRIVE` and `HOMEPATH` will be tried. This is done by the `os.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.)

参见

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.

参见

Building Python modules on MS Windows platform with MinGW

  针对 MinGW 环境生成必要的库的相关信息

备注

1

  这也意味着你可以将现有的全部 COFF 库替换为同名的 OMF 库。

2

  请查看 https://www.sourceware.org/cygwin/ 了解更多信息

3

  你将没有可用的 POSIX 模拟，但你也将不再需要 `cygwin1.dll`。