Cannot get the value from dogpile.cache from different modules.

[Mark Lawrence]

On 29/12/2015 17:27, xeon Mailinglist wrote:
> On Tuesday, December 29, 2015 at 5:15:24 PM UTC, Mark Lawrence wrote:
>> On 29/12/2015 15:20, xeon Mailinglist wrote:
>>> On Tuesday, December 29, 2015 at 11:16:10 AM UTC, xeon Mailinglist wrote:
>>>> 1. How do I create a global variable that can be accessed by all classes?
>>>>
>>>> 2. I am using `dogpile.cache` to store data in the cache [1], but if I set and get the same key from different modules, I don't get the value. Here is an example in [2]. The value than I get is `NO_VALUE.NO_VALUE`. Why this happens?
>>>>
>>>> setter is the setter.py
>>>> getter is the getter.py
>>>> Memoize is the file in [1].
>>>>
>>>>
>>>> [1] my dogpile class `Memoize.py`
>>>>
>>>>       from dogpile.cache import make_region
>>>>
>>>>       region = make_region().configure('dogpile.cache.memory')
>>>>
>>>>       def save(key, value):
>>>>         """
>>>>         general purpose method to save data (value) in the cache
>>>>
>>>>         :param key (string) key of the value to be saved in cache
>>>>         :param value (any type) the value to be saved
>>>>         """
>>>>         region.set(key, value)
>>>>
>>>>
>>>>       def get(key):
>>>>         """
>>>>         general purpose method to get data from the cache
>>>>
>>>>         :param key (string) key of the data to be fetched
>>>>         :return value (any type) data to be returned from the cache
>>>>         """
>>>>         return region.get(key)
>>>>
>>>>
>>>> [2] My python example
>>>>
>>>> `setter.py`
>>>>
>>>>       def myset(value):
>>>>         Memoize.save("myvalue", value)
>>>>
>>>> `getter.py`
>>>>
>>>>      def myget():
>>>>         return Memoize.get("myvalue") <- this value is NO_VALUE. NO_VALUE
>>>>
>>>> My class:
>>>>
>>>>       setter.myset(123)
>>>>       getter.myget()
>>>
>>> The idea that I get from dogpile, is that in each module (getter.py, or setter.py) there is a dictionary where the values are stored in the backend. Hence, getter.py has its dictionary and setter.py has its dictionary also. In the end, there is not a single dictionary where all the values should be put. And I want a single dictionary.
>>>
>>
>> Then put everything in one file.  Three files for the amount of code you
>> show above is nonsensical.  You might like to read
>> http://dirtsimple.org/2004/12/python-is-not-java.html and in response to
>> that http://dirtsimple.org/2004/12/java-is-not-python-either.html
>>
>> --
>> My fellow Pythonistas, ask not what our language can do for you, ask
>> what you can do for our language.
>>
>> Mark Lawrence
>
> Here is the full class that I use to store the data.
>
> from dogpile.cache import make_region
>
>
> # my_dictionary = {}
> region = make_region().configure('dogpile.cache.memory')
> # arguments={"cache_dict":my_dictionary})
> class Cache:
>
>      @staticmethod
>      def save(key, value):
>          """
>          general purpose method to save data (value) in the cache
>
>          :param key (string) key of the value to be saved in cache
>          :param value (any type) the value to be saved
>          """
>          region.set(key, value)
>
>      @staticmethod
>      def get(key):
>          """
>          general purpose method to get data from the cache
>
>          :param key (string) key of the data to be fetched
>          :return value (any type) data to be returned from the cache
>          """
>          return region.get(key)
>
>
>      @staticmethod
>      def get_or_create(key):
>          """
>          General purpose method to get data from the cache. If the value does not exist, it creates a list
>
>          :param: key (string) key of the data to be fetched
>          :return value (any type) data to be returned from the cache
>          """
>          return region.get_or_create(key, list)
>
>      @staticmethod
>      def set_job_predictions(rank_list):
>          Cache.save("job_predictions", rank_list)
>
>      @staticmethod
>      def get_job_predictions():
>          return Cache.get("job_predictions")
>

I get the strong impression that you're reinventing wheels and doing it 
so badly that they're triangular.  Have you tried pypi 
https://pypi.python.org/pypi for proven code that could do the job for you?

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence