python跨版本包管理方案（pyenv + pipenv）

背景

通过对pyenv的探索，已经掌握pyenv对python多版本的管理方法。

同时pyenv可以集成virtualenv，实现多项目需求的独立环境的搭建，

from（https://github.com/pyenv/pyenv-virtualenv）

问题是，对于项目的管理， 我们缺少一个依赖的配置清单，类似 node的 package.json

这个可以通过pip freeze来生成requirement.txt文件解决。

但是这个方法，具有一些问题，每次pip install后，需要主动调用pip freeze来更新配置清单。

针对这个问题，

于是pipenv闪亮出场

https://pipenv.pypa.io/en/latest/

针对新的安装包， 只需要 pipenv install xxx， 就可以将新的文件更新到 pipfile中。

体验跟node的npm类似。

于是针对包管理的角度， 我们引入新的python跨版本包管理方案

pyenv + pipenv

pyenv -- 跨python版本的os环境管理。

pipenv -- 跨多个项目的运行环境管理。

pyenv

https://github.com/pyenv/pyenv

pyenv does...

• Let you change the global Python version on a per-user basis.
• Provide support for per-project Python versions.
• Allow you to override the Python version with an environment variable.
• Search commands from multiple versions of Python at a time. This may be helpful to test across Python versions with tox.

pipenv

https://pipenv.pypa.io/en/latest/

The problems that Pipenv seeks to solve are multi-faceted:

• You no longer need to use pip and virtualenv separately. They work together.
• Managing a requirements.txt file can be problematic, so Pipenv uses Pipfile and Pipfile.lock to separate abstract dependency declarations from the last tested combination.
• Hashes are used everywhere, always. Security. Automatically expose security vulnerabilities.
• Strongly encourage the use of the latest versions of dependencies to minimize security risks arising from outdated components.
• Give you insight into your dependency graph (e.g. $ pipenv graph).
• Streamline development workflow by loading .env files.