Linux上的两个版本的python。 如何将软件包安装到特定版本的python？

Question

I am using Linux CentOs server. In my server two version of python were installed - 2.6 and 2.7. Both path are entered in to path variable.

I am trying to install pip using following command:

> sudo yum install python-pip 

But it installed to python2.6 ( /usr/bin/python ). So If I am trying to install package to python using pip it goes to python2.6. For example

> pip install XlsxWriter

First of all I want to install pip to python2.7 version and then have to some packages. Path of python2.7 is /usr/local/bin/python2.7 . How do I manage packages for different versions of python? (I don't want to change my default python version (2.6).)

My second question is... My project needs 8 python packages. How do I install all packages in a single command? Is there any concept like package.json (which is used for nodejs) or composer.json (which is used for php) in python? I heard about setup.py but I could not clear about that. Is this setup.py concept similar to package.json?

Answer 1

If you want to have control over what Python version you're using, I'd suggest considering virtual environments .

You can then create a stand-alone virtual environment for each project and use the Python version you need.

This will create a virtual environment for your project with Python 2.7, install <package> and deactivate the virtual environment.

cd my_project_folder
virtualenv -p /usr/bin/python2.7 venv
source venv/bin/activate
pip install <package>
deactivate

As for your second question, I recommend using pip freeze and pip install -r ...

First, install all the packages you need:

source venv/bin/activate
pip install <package1>, <package2>,...

Then save the list of packages with their current versions:

pip freeze > requirements.txt

This will create a requirements.txt file that you can distribute with the project. When somebody wants to install all the dependencies, they will need to do:

pip install -r requirements.txt

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For Python 3, virtual environments are supported by default - venv .

Answer 2

Say you have two python versions installed 2.7 and 3.5,

Set the Environment variables

• set python2 as the env variable for python2.7
• set python as evn variable for python3.5

Install packages for python2: python2 -m pip install < package-name >

Install packages for python3: python -m pip install < package-name > or pip install < package-name>

Answer 3

Try which pip , choose your pip

then simply do sudo /path_to_your_version_of_pip/pip install your module