我知道pip是python包的包管理器。但是,我在IPython的网站上看到了使用conda安装IPython的安装。

我可以用pip安装IPython吗?当我已经有pip时,为什么我要使用conda作为另一个python包管理器?

pip和conda的区别是什么?


当前回答

PIP是一个包管理器。

Conda既是包管理器,也是环境管理器。

细节:

依赖项检查

Pip and conda also differ in how dependency relationships within an environment are fulfilled. When installing packages, pip installs dependencies in a recursive, serial loop. No effort is made to ensure that the dependencies of all packages are fulfilled simultaneously. This can lead to environments that are broken in subtle ways, if packages installed earlier in the order have incompatible dependency versions relative to packages installed later in the order. In contrast, conda uses a satisfiability (SAT) solver to verify that all requirements of all packages installed in an environment are met. This check can take extra time but helps prevent the creation of broken environments. As long as package metadata about dependencies is correct, conda will predictably produce working environments.

参考文献

理解康达和皮普

其他回答

I may have found one further difference of a minor nature. I have my python environments under /usr rather than /home or whatever. In order to install to it, I would have to use sudo install pip. For me, the undesired side effect of sudo install pip was slightly different than what are widely reported elsewhere: after doing so, I had to run python with sudo in order to import any of the sudo-installed packages. I gave up on that and eventually found I could use sudo conda to install packages to an environment under /usr which then imported normally without needing sudo permission for python. I even used sudo conda to fix a broken pip rather than using sudo pip uninstall pip or sudo pip --upgrade install pip.

其他答案对细节进行了合理的描述,但我想强调一些高级点。

PIP是一个包管理器,可以方便地安装、升级和卸载python包。它也适用于虚拟python环境。

Conda是任何软件(安装、升级和卸载)的包管理器。它还适用于虚拟系统环境。

conda设计的目标之一是方便用户所需的整个软件堆栈的包管理,其中一个或多个python版本可能只是一小部分。这包括低级库,如线性代数,编译器,如Windows上的mingw,编辑器,版本控制工具,如Hg和Git,或任何其他需要分发和管理的工具。

对于版本管理,pip允许您在多个python环境之间切换和管理。

Conda允许您在多个通用环境之间切换和管理,在这些环境中,许多其他东西的版本号可能不同,比如c库、编译器、测试套件或数据库引擎等等。

Conda不是以Windows为中心的,但在Windows上,当需要安装和管理需要编译的复杂科学包时,它是目前可用的最好的解决方案。

当我想到在Windows上通过pip编译许多这些包,或者在需要编译时调试失败的pip安装会话时,我浪费了多少时间,我想哭。

最后一点,Continuum Analytics还提供(免费的)binstar.org(现在叫anaconda.org),允许常规的软件包开发人员创建他们自己的自定义(构建的!)软件堆栈,他们的软件包用户可以从中安装conda。

要回答最初的问题, 对于安装包,PIP和Conda是完成相同任务的不同方式。两者都是安装包的标准应用程序。主要的区别是包文件的来源。

PIP/PyPI将有更多的“实验性”包,或者更新的、不太常见的包版本 Conda通常会有更完善的包或版本

一个重要的警告提示:如果使用两个源(pip和conda)在同一环境中安装包,以后可能会导致问题。

重建环境将更加困难 修复包不兼容性变得更加复杂

最佳实践是选择一个应用程序(PIP或Conda)来安装包,并使用该应用程序安装所需的任何包。 然而,仍然有许多例外或理由在conda环境中使用pip,反之亦然。 例如:

如果您需要的包只存在于一个包上,则 其他人没有。 您需要一个只在一个环境中可用的特定版本

免责声明:这个答案描述的是十年前的情况,当时pip还不支持二进制包。Conda是专门为更好地支持构建和分发二进制包而创建的,特别是带有C扩展的数据科学库。作为参考,pip只获得了带轮子的便携式二进制包的广泛支持(2013年的pip 1.4)和manylinux1规范(2016年3月的pip 8.1)。查看最近的答案了解更多历史。

以下是一个简短的概述:

pip

只支持Python包。 从源代码编译所有内容。编辑:pip现在安装二进制车轮,如果他们是可用的。 受到核心Python社区的支持(即Python 3.4+包含自动引导pip的代码)。

conda

Python agnostic. The main focus of existing packages are for Python, and indeed Conda itself is written in Python, but you can also have Conda packages for C libraries, or R packages, or really anything. Installs binaries. There is a tool called conda build that builds packages from source, but conda install itself installs things from already built Conda packages. External. conda is an environment and package manager. It is included in the Anaconda Python distribution provided by Continuum Analytics (now called Anaconda, Inc.).

conda is an environment manager written in Python and is language-agnostic. conda environment management functions cover the functionality provided by venv, virtualenv, pipenv, pyenv, and other Python-specific package managers. You could use conda within an existing Python installation by pip installing it (though this is not recommended unless you have a good reason to use an existing installation). As of 2022, conda and pip are not fully aware of one another package management activities within a virtual environment, not are they interoperable for Python package management.

在这两种情况下:

用Python编写 开源(conda是BSD, pip是MIT) 警告:虽然conda本身是开源的,但包存储库由Anaconda Inc托管,并且在商业使用方面有限制。

The first two bullet points of conda are really what make it advantageous over pip for many packages. Since pip installs from source, it can be painful to install things with it if you are unable to compile the source code (this is especially true on Windows, but it can even be true on Linux if the packages have some difficult C or FORTRAN library dependencies). conda installs from binary, meaning that someone (e.g., Continuum) has already done the hard work of compiling the package, and so the installation is easy.

如果您对构建自己的包感兴趣,也有一些不同之处。例如,pip构建在setuptools之上,而conda使用自己的格式,这有一些优点(比如是静态的,并且与Python无关)。

pip仅用于Python

conda只适用于Anaconda +其他科学包,如R依赖等。并不是每个人都需要蟒蛇,因为它已经和Python一起出现了。Anaconda主要是为那些做机器学习/深度学习等的人准备的。普通的Python开发人员不会在他的笔记本电脑上运行Anaconda。