csparpa / pyowm-cache-adapters

A set of simple Python adapters allowing the PyOWM library to leverage external cache systems

pyowm-cache-adapters

A set of simple draft adapters allowing the PyOWM library to leverage external cache systems. The code relies on the Python bindings for the adapted system.

Supported cache systems

• Memcached
• Redis
• MongoDB

More to come...

License

MIT license

Installation

1. Of course, you need to install the PyOWM library before :-) Use pip
2. Install the Python bindings for the cache system/s you need to adapt:
   • python-memcached
   • redis-py
   • pymongo
3. Download the adapters package
4. Place it somewhere you can reach via your PYTHONPATH variable (the PyOWM installation folder is OK)

Wiring

There are two ways...

The easy one

1. Wire the adapters into a configuration module that you setup and put in a location reachable from your PYTHONPATH. Eg: say your config file is mypyowmconfig/myconfig.py and mypyowmconfig is somewhere in your PYTHONPATH:

   # Content of your own PyOWM config module
   from pyowm-cache-adapters import redis_adapter  # This is where you installed the adapters
   cache = nullcache.RedisAdapter()
   # [...] (other config values)
   

2. Instantiate the library injecting a reference to your own config module. Eg:

   import pyowm
   owm = pyowm.OWM(None, None, 'mypyowmconfig.myconfig')  # This loads the config values from your module
   

   More about PyOWM config module on the PyOWM wiki.

The difficult one

1. Find the configurationXX.py file which is specific for the web API version you are currently using. This will likely be in /usr/local/lib/python2.6/dist-packages/pyowm/webapi25/config25.py for Unix-like envs or in C:\Python27\Lib\site-packages\pyowm\webapi25\config25.py for Windows envs.

2. Open the file and spot this line:

   # Cache provider to be used
   cache = NullCache()

   and change it accordingly to the adapter you need. In example, for Memcached:

   # Cache provider to be used
   # cache = NullCache()  # <--- comment/remove this line
   from pyowm_cache_adapter.memcached_adapter import MemcachedAdapter
   cache = MemcachedAdapter( [... parameters ...] )

   (be careful not to miss the import statement)

Modifying

The provided adapters are just intended to be drafts: modify them accordingly to your application-specific needs.

There's only one thing that you must bear in mind: each adapter must subclass the the pyowm.abstractions.owmcache.OWMCache abstract class for it to work into the PyOWM library.

Bugs

Please signal any bugs you may encounter.