Lessons from Python

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From Intermediate Python Practical Techniques for Deeper Skill Development by Steve Holden, O'Reilly Media April 2014

From personal usage

virtualenv
- virtualenvwrapper
  - mkvirtualenv --python=/usr/bin/python3 X
  - workon to list available virtualenvs
  - workon X to active virtualenv X
- updating (e.g. from 3.4 to 3.5, assuming 3.5 as make altinstall rather than system default)
  - cd targetenv
  - pip freeze > requirments.txt
  - deactivate targetenv
  - mv ~/.virtualenvs/targetenv{,-backup3.4}
  - mkvirtualenv --python=/usr/local/bin/python3.5 -r requirments.txt
    - pip install might fail if so pip install -r requirments.txt after
    - eventually pip upgrades after
  - ... and testing to make sure it all still works
matplotlib
- plt.close('all') to close all opened plots, practical during iPython tests
Python 3
- print('This is working!')
- python -m http.server 8000
- compiled 3.4 from source in order
  - mostly with quite a few issues with 3.2 that comes with Debian stable
- worked out well with virtualenv while making sure pip is up to date
  - including with numpy, scipy, matplotlib, ipython
coverage.py
- http://nedbatchelder.com/code/coverage/
  - motivated by https://docs.python.org/3/howto/pyporting.html
fancier output
- https://docs.python.org/2/tutorial/inputoutput.html#fancier-output-formatting
debugging
- python -m pdb mycode.py
  - (Pdb) break 68 set breakpoint at the line 68
  - (Pdb) c continue until the next breakpoint
  - allow to test for the different values interactively
supybot-plugin-create : Supybot command to generate a plugin template (basic source and license)

Websites

Django
- note that if working with Git and branches then the migrations and the DB in particular *have* to be tracked
  - typical error else OperationalError
- working with Jupyter/notebooks
  - available via own alias jupyertunnel
  - http://kaflurbaleen.blogspot.be/2015/09/using-ipython-notebook-with-django-on.html
- models
  - can't be modified (e.g. adding a property) without discarding the DB and running syncdb again
  - http://stackoverflow.com/questions/1142378/django-why-some-fields-clashes-with-other
- views
  - https://docs.djangoproject.com/en/1.5/ref/class-based-views/generic-display/
- templates
  - https://docs.djangoproject.com/en/dev/topics/templates/
  - to handle CSS, JS, etc https://docs.djangoproject.com/en/1.5/howto/static-files/
- key apps
  - https://docs.djangoproject.com/en/1.5/topics/auth/
  - django.contrib.auth https://docs.djangoproject.com/en/1.5/ref/contrib/auth/
- to find new apps
  - https://www.djangopackages.com with its grid view a la WikiMatrix
    - e.g. https://github.com/omab/django-social-auth
- Djangos requestresponse cycle a visual guide
  - http://www.reddit.com/r/django/comments/2vjyrc/djangos_requestresponse_cycle_a_visual_guide/

Sysadmin

Python for system administrators by James Knowlton, IBM DeveloperWorks 2007
Python for Unix and Linux System Administration by Noah Gift and Jeremy M. Jones, O'Reilly Media 2008
pyp - Python Power at the Prompt aka The Pyed Piper
- the other way around, using Python within scripts rather than replacing bash or Perl
Python and sysadmin I by Guixing Bai, 2009

On going projects

Past projects

OpenCV posture holder
rewrite the PHP IRC/Wiki linker (offline) based on
- Sample Python Client XMLRPC from Dokuwiki
- Reading and Writing Files from Input and Output in Python v2.6.1 documentation
discovering Google App Engine (cheat sheet) by working on
- Distributed pmwiki statistics
  - Use appcfg.py to upload and deploy your application code.
  - learn more
- deploy sheclicked.it
- WikiBot and the possibility to monitor a set of pages for corrections/suggestions/etc
  - check also hooks/HTTP callback mechanism

Principle

read our current position on the log file (last successful writing in the wiki)
1. if no current position, create it and start at 0
read the log file from this position to the end of the file
write the content in the wiki
update the current position in the log file to the current end of file
return an explicit value and quit

References

Learn Python in 10 minutes from Poromenos' Stuff, 2006
The Python Tutorial from Python v2.6.1 documentation, December 2008
HOWTO Use Python in the web by Marek Kubica for Python v2.6.1 documentation
Getting Started with App Engine in Eclipse by Mano Marks, September 2008
- Based on Configuring Eclipse on Windows to Use With Google App Engine by Joscha Feth, June 2008
Python basics for PHP developers by Thomas Myer, IBM developerWorks 2010
http://stackoverflow.com/questions/947810/how-to-save-a-python-interactive-session
http://overapi.com/python/
Intermediate Python by Steve Holden, O'Reilly Media April 2014

To explore

http://nbviewer.ipython.org aka Jupyter
- way to avoid going through __main__ ?
- ~~problem with finding files~~
  - e.g. http://pyphen.org
  - possibly related to environment variables
    - solved by removing and re-installing inside the virtualenv
- http://nbviewer.ipython.org/github/AstroHackWeek/AstroHackWeek2014/blob/master/day1/ipython/Pair%20programming%20with%20an%20IPython%20Notebook%20Server.ipynb
following Friday meeting with Ludo
- Google Python Style Guide
- Pylint - code analysis for Python
  - http://docs.pylint.org/output.html
  - analyzes Python source code looking for bugs and signs of poor quality.
  - http://docs.pylint.org/tutorial.html

Note

My notes on Tools gather what I know or want to know. Consequently they are not and will never be complete references. For this, official manuals and online communities provide much better answers.

Python {Tools}