====== Best Practices (Python) ======

===== Check if dictionary contains key, if not return default value =====
<code python>
# not so good
if 'owner' in roledict:
    owner = roledict['owner']
else:
    owner = admin
    
# just slightly better, still not good
try:
    owner = roledict['owner']
except KeyError:
    owner = admin
    
# better
owner = roledict.get('owner', admin)
</code>

===== Invoking subprocesses =====
In order to spawn new processes like you would do in a shell, use the [[http://docs.python.org/library/subprocess.html|subprocess]] module of the Python standard library.
It should be used instead of the ''os.system'' module.


===== Object Oriented Programming =====

**SOLID** design princibles: https://www.youtube.com/watch?v=pTB30aXS77U

  * **S**ingle responsibility
  * **O**pen/Closed  
  * **L**iskov substitution  
  * **I**nterface segregation  
  * **D**ependency inversion  


{{tag>"python" "best practices"}}