python包管理工具pip

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  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: [e-mail]
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。