你可以使用一个名为 pip 的程序来安装、升级和移除软件包。默认情况下 pip
将从 Python Package Index <https://pypi.org> 安装软件包。你可以在浏览器中访问 Python Package Index 或是使用 pip
受限的搜索功能:
(tutorial-env) $ pip search astronomy
skyfield - Elegant astronomy for Python
gary - Galactic astronomy and gravitational dynamics.
novas - The United States Naval Observatory NOVAS astronomy library
astroobs - Provides astronomy ephemeris to plan telescope observations
PyAstronomy - A collection of astronomy related tools for Python.
...
pip
有许多子命令:“search”、“install”、“uninstall”、“freeze”等等。(请参阅 python pip安装 指南以了解 pip
的完整文档。)
您可以通过指定包的名称来安装最新版本的包:
(tutorial-env) $ pip install novas
Collecting novas
Downloading novas-3.1.1.3.tar.gz (136kB)
Installing collected packages: novas
Running setup.py install for novas
Successfully installed novas-3.1.1.3
您还可以通过提供包名称后跟 ==
和版本号来安装特定版本的包:
(tutorial-env) $ pip install requests==2.6.0
Collecting requests==2.6.0
Using cached requests-2.6.0-py2.py3-none-any.whl
Installing collected packages: requests
Successfully installed requests-2.6.0
如果你重新运行这个命令,pip
会注意到已经安装了所请求的版本并且什么都不做。您可以提供不同的版本号来获取该版本,或者您可以运行 pip install --upgrade
将软件包升级到最新版本:
(tutorial-env) $ pip install --upgrade requests
Collecting requests
Installing collected packages: requests
Found existing installation: requests 2.6.0
Uninstalling requests-2.6.0:
Successfully uninstalled requests-2.6.0
Successfully installed requests-2.7.0
pip uninstall
后跟一个或多个包名称将从虚拟环境中删除包。
pip show
将显示有关特定包的信息:
(tutorial-env) $ pip show requests
---
Metadata-Version: 2.0
Name: requests
Version: 2.7.0
Summary: Python HTTP for Humans.
Home-page: http://python-requests.org
Author: Kenneth Reitz
Author-email: me@kennethreitz.com
License: Apache 2.0
Location: /Users/akuchling/envs/tutorial-env/lib/python3.4/site-packages
Requires:
pip list
将显示虚拟环境中安装的所有软件包:
(tutorial-env) $ pip list
novas (3.1.1.3)
numpy (1.9.2)
pip (7.0.3)
requests (2.7.0)
setuptools (16.0)
pip freeze` 将生成一个类似的已安装包列表,但输出使用 pip install
期望的格式。一个常见的约定是将此列表放在 requirements.txt
文件中:
(tutorial-env) $ pip freeze > requirements.txt
(tutorial-env) $ cat requirements.txt
novas==3.1.1.3
numpy==1.9.2
requests==2.7.0
然后可以将 requirements.txt
提交给版本控制并作为应用程序的一部分提供。然后用户可以使用 install -r
安装所有必需的包:
(tutorial-env) $ pip install -r requirements.txt
Collecting novas==3.1.1.3 (from -r requirements.txt (line 1))
...
Collecting numpy==1.9.2 (from -r requirements.txt (line 2))
...
Collecting requests==2.7.0 (from -r requirements.txt (line 3))
...
Installing collected packages: novas, numpy, requests
Running setup.py install for novas
Successfully installed novas-3.1.1.3 numpy-1.9.2 requests-2.7.0
pip
有更多选择。有关 pip
的完整文档, 请参阅Python教程。