python virtualenv & pip in 90 minutes

Larry cai <larry.caiyu#gmail.com>

Agenda

Python Virtualenv & Pip in 90 minutes

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What is Virtualenv & Pip ? Environment : Install Virtualenv on windows

(Linux is easy) Exercise 1: Create own environment using

virtualenv Exercise 2: Learn pip command Exercise 3: Create own Pip package Exercise 4: Make scripts runnable directly Bonus Exercise: Share your scripts outside

!!!! Exercise are created by me, and some introduction slides are copied from http://www.slideshare.net/webdebs/virtualenv-12727213

Problem for using python How to install the packages ?

(download & python setup.py install) How to use different python versions

(2.6,2.7,3.x..)? How to install different packages (0.2,0.3.) How to test some packages without ruin the

system How to delivery your python codes to other ? How to verify them ? …


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What is Pip & PyPi & Virtualenv pip is a tool for installing and managing

Python packages It’s a replacement for easy_install.

PyPi (Python Pakage Index) is a repository of software for Python and currently count 33429 package https://pypi.python.org/pypi

Virtualenv is a tool to isolate your python environment


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Environment


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Python 2.7.x In Windows with Git Bash http://

www.python.org/ftp/python/2.7.3/python-2.7.3.msi (2.7.5 has issues with pycrypto)

Add into Path Install Pip (Python package management)

curl -O http://python-distribute.org/distribute_setup.py python distribute_setup.py easy_install pip

Install Virtualenv pip --version pip install virtualenv

http://stackoverflow.com/questions/4750806/how-to-install-pip-on-windows

WHY virtual environments ? Isolation - Python packages and even version

live in their own planet :) Permissions - No sudoers, the environment

is mine!!! Organization - each project can maintain its

own requirements file of Python packages. No-Globalization – don’t require installing

stuff globally on the system.


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Exercise 1: Create own environment


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Create own environment$ pip list # if error, $ pip install --upgrade setuptools

$ cd ~

$ virtualenv venv

$ find venv

$ . venv/Scripts/activate

$ pip list

$ pip install python-jenkins xunitparser

$ pip list

$ find ~/venv | grep unit

$ deactivate

$ pip list

Exercise 2: learn pip Install , uninstall, upgrade packages

$ . ~/venv/Scripts/activate$ pip install junit-xml # latest version $ pip uninstall junit-xml$ pip install junit-xml==1.2 # specific version $ pip install --upgrade junit-xml

Generate package list and restore$ pip list$ pip freeze > requirements.txt$ pip uninstall junit-xml xunitparser$ pip install -r requirements.txt

Install local packages from mirror$ pip install --index-url http://my.package.repo/simple/ <yourpackage>


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http://www.pip-installer.org/en/latest/usage.html

Exercise 3: Create your own package Write a simple hello.py under hello folder

print “hello world”

Write a setup.pyfrom distutils.core import setup setup(name=‘hello', version=‘0.0.1', py_modules=[‘hello'], )

Package and install$ python setup.py sdist

$ pip install dist/hello.0.0.1.zip

$ find ~/venv | grep hello

Change version to “0.0.2” and do it again


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http://docs.python.org/2/distutils/introduction.html

Exercise 4: make your scripts runnable Make the hello.py can be runnable after

installationfrom distutils.core import setup setup(name=‘hello', version=‘0.0.3’, scripts=[‘hello.py’], py_modules=[‘hello'], )

Testing it$ python setup.py sdist

$ pip install dist/hello.0.0.3.zip

$ find ~/venv | grep hello

Make it runnable (change hello.py ..)$ hello.py # bingo, so simple


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Bonus: Share your scripts outside https://pypi.python.org/pypi register and

$ python setup.py register sdist upload # that’s all

Simpler than your thinking ….


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Summary Using virtualenv to isolate your python

environment Use pip to package Host in github and shared in PyPi repository

Enjoy python programming


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Reference Slides

http://www.slideshare.net/webdebs/virtualenv-12727213

Usage link http://www.pip-installer.org/en/latest/usage.html https://pypi.python.org/pypi http://docs.python.org/2/distutils/introduction.html https://pypi.python.org/pypi/virtualenv


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python virtualenv & pip in 90 minutes

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