A collection of design patterns and idioms in Python.

Jeroen 2efc2204a0 PEP8 changes		vor 11 Jahren
.gitignore	2476b4b5dd Remove __pycache__ and add __pycache__ to .gitignore	vor 11 Jahren
3-tier.py	6211358b71 append_output.sh for 3-tier and null	vor 11 Jahren
README.md	4b81a4a6e8 removing null, it is not considered pythonic	vor 11 Jahren
abstract_factory.py	760d693ce1 Small change in output : Methods of factory should print 'We have...' since they are the once only producing the object', object specific methods can start from 'It is ...'	vor 11 Jahren
adapter.py	5d794ceecb Your code is too weak for PEP8. You lack DISCIPLINE	vor 11 Jahren
append_output.sh	ba8afd7a72 added the state variable to borg and improved the README	vor 11 Jahren
borg.py	ba8afd7a72 added the state variable to borg and improved the README	vor 11 Jahren
bridge.py	5d794ceecb Your code is too weak for PEP8. You lack DISCIPLINE	vor 11 Jahren
builder.py	5d794ceecb Your code is too weak for PEP8. You lack DISCIPLINE	vor 11 Jahren
catalog.py	5d794ceecb Your code is too weak for PEP8. You lack DISCIPLINE	vor 11 Jahren
chain.py	1878a5310b Minor pep8 changes. Most salient is that membership test should be 'x not in y' whereas 'not x in y' was being used.	vor 11 Jahren
command.py	5d794ceecb Your code is too weak for PEP8. You lack DISCIPLINE	vor 11 Jahren
composite.py	5d794ceecb Your code is too weak for PEP8. You lack DISCIPLINE	vor 11 Jahren
decorator.py	2efc2204a0 PEP8 changes	vor 11 Jahren
facade.py	5d794ceecb Your code is too weak for PEP8. You lack DISCIPLINE	vor 11 Jahren
factory_method.py	5d794ceecb Your code is too weak for PEP8. You lack DISCIPLINE	vor 11 Jahren
flyweight.py	5d794ceecb Your code is too weak for PEP8. You lack DISCIPLINE	vor 11 Jahren
foo.txt	3511c20bf6 Added foo.txt for command.py script.	vor 12 Jahren
graph_search.py	1878a5310b Minor pep8 changes. Most salient is that membership test should be 'x not in y' whereas 'not x in y' was being used.	vor 11 Jahren
iterator.py	5d794ceecb Your code is too weak for PEP8. You lack DISCIPLINE	vor 11 Jahren
mediator.py	5d794ceecb Your code is too weak for PEP8. You lack DISCIPLINE	vor 11 Jahren
memento.py	5d794ceecb Your code is too weak for PEP8. You lack DISCIPLINE	vor 11 Jahren
mvc.py	5d794ceecb Your code is too weak for PEP8. You lack DISCIPLINE	vor 11 Jahren
observer.py	1878a5310b Minor pep8 changes. Most salient is that membership test should be 'x not in y' whereas 'not x in y' was being used.	vor 11 Jahren
pool.py	5d794ceecb Your code is too weak for PEP8. You lack DISCIPLINE	vor 11 Jahren
prototype.py	2efc2204a0 PEP8 changes	vor 11 Jahren
proxy.py	5d794ceecb Your code is too weak for PEP8. You lack DISCIPLINE	vor 11 Jahren
publish_subscribe.py	1878a5310b Minor pep8 changes. Most salient is that membership test should be 'x not in y' whereas 'not x in y' was being used.	vor 11 Jahren
state.py	5d794ceecb Your code is too weak for PEP8. You lack DISCIPLINE	vor 11 Jahren
strategy.py	5d794ceecb Your code is too weak for PEP8. You lack DISCIPLINE	vor 11 Jahren
template.py	f61504c1bd Add output to bottom of scripts	vor 11 Jahren
visitor.py	5d794ceecb Your code is too weak for PEP8. You lack DISCIPLINE	vor 11 Jahren

python-patterns

A collection of design patterns and idioms in Python.

When an implementation is added or modified, be sure to update this file and rerun append_output.sh (eg. ./append_output.sh borg.py) to keep the output comments at the bottom up to date.

Current Patterns:

Pattern	Description
3-tier	data<->business logic<->presentation separation (strict relationships)
abstract_factory	use a generic function with specific factories
adapter	adapt one interface to another using a whitelist
borg	a singleton with shared-state among instances
bridge	a client-provider middleman to soften interface changes
builder	call many little discrete methods rather than having a huge number of constructor parameters
catalog	general methods will call different specialized methods based on construction parameter
chain	apply a chain of successive handlers to try and process the data
command	bundle a command and arguments to call later
composite	encapsulate and provide access to a number of different objects
decorator	wrap functionality with other functionality in order to affect outputs
facade	use one class as an API to a number of others
factory_method	delegate a specialized function/method to create instances
flyweight	transparently reuse existing instances of objects with similar/identical state
graph_search	(graphing algorithms, not design patterns)
iterator	structure repeated, identical calls as a generator
mediator	an object that knows how to connect other objects and act as a proxy
memento	generate an opaque token that can be used to go back to a previous state
mvc	model<->view<->controller (non-strict relationships)
observer	provide a callback for notification of events/changes to data
pool	preinstantiate and maintain a group of instances of the same type
prototype	use a factory and clones of a prototype for new instances (if instantiation is expensive)
proxy	an object funnels operations to something else
publish_subscribe	a source syndicates events/data to 0+ registered listeners
state	logic is org'd into a discrete number of potential states and the next state that can be transitioned to
strategy	selectable operations over the same data
template	an object imposes a structure but takes pluggable components
visitor	invoke a callback for all items of a collection

README.md

python-patterns