learn Python virtualenv & pip in 90 minutes by doing exercise

1. Larry cai <larry.caiyu#gmail.com>

2. Agenda
Python Virtualenv & Pip in 90 minutes2
 What isVirtualenv & Pip ?
 Environment : InstallVirtualenv 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

3. 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 ?
 …
Python Virtualenv & Pip in 90 minutes3

4. 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
Python Virtualenv & Pip in 90 minutes4

5. Environment
Python Virtualenv & Pip in 90 minutes5
 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
 InstallVirtualenv
 pip --version
 pip install virtualenv
http://stackoverflow.com/questions/4750806/how-to-install-pip-on-windows

6. 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.
Python Virtualenv & Pip in 90 minutes6

7. Exercise 1: Create own environment
Python Virtualenv & Pip in 90 minutes7
 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

8. 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>
Python Virtualenv & Pip in 90 minutes8
http://www.pip-installer.org/en/latest/usage.html

9. Exercise 3: Create your own package
 Write a simple hello.py under hello folder
print “hello world”
 Write a setup.py
from 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
Python Virtualenv & Pip in 90 minutes9
http://docs.python.org/2/distutils/introduction.html

10. Exercise 4: make your scripts runnable
 Make the hello.py can be runnable after installation
from 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
Python Virtualenv & Pip in 90 minutes10

11. 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 ….
Python Virtualenv & Pip in 90 minutes11

12. Summary
 Using virtualenv to isolate your python environment
 Use pip to package
 Host in github and shared in PyPi repository
 Enjoy python programming
Python Virtualenv & Pip in 90 minutes12

13. 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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