Sejings

Sejings is meant to be a quick and simple tool to rapidly integrate project sejings. The problem I've seen many times with libraries is that it's often hard to have a way for the user to change aspects or functionality deep in a library. Scientific libraries often have arguments for a function that are unavailable to a developer because they're hidden behind three function calls. One attempt to solve this is to pass along keyword arguments, which leads to documentation and maintainability issues. This is evident by the popularity of **kwargs in many data science libraries. The other solution is to work with dictionaries similar to matplotlib's rcParams. Yet this leads to a tedious and time consuming developer experience by forcing if xxx is None checks everywhere.

To show you my solution let's first start of with a rcParams style function:

def add(*nums, cache=None, cache_path=None):
    
    if cache is None:
        cache = sejings['cache']
    if cache_path is None:
        cache_path = sejings['cache.path']
    
    result = sum(nums)
    
    if cache: # True
        save_to_cache(result, cache_path) #'/some/dir/path'
    
    return result

Obviously dictionaries would be computationally the fastest way to accomplish sejings. This project is meant to be friendly to developers consuming packages and to encourage rapid development over absolute runtime speed. We're using Python after all, right?

Usage

Import sejings and create the sejings you need:

from sejings import sejings

sejings.cache = True
sejings.cache.path = '/some/dir/path'

To evaluate sejings passed into a function as an argument use the @extract_sejings decorator. This will evaluate all sejings in the function definition and in the arguments being passed into the function:

from sejings import extract_sejings

@extract_sejings
def add(*nums, cache=sejings.cache, cache_path=sejings.cache.path):
    result = sum(nums)
    
    if cache: # True
        save_to_cache(result, cache_path) #'/some/dir/path'
    
    return result

A branch is also evaluated when an endpoint is called.

assert sejings.cache()
assert sejings.cache.path() == '/some/dir/path'

def add(*nums, cache=sejings.cache, cache_path=sejings.cache.path):
    result = sum(nums)
    
    if cache(): # True
        save_to_cache(result, cache_path()) #'/some/dir/path'
    
    return result

In some cases defining arguments as a Sejings object may be desired. This is accomplished by adding the argument name to the @extract_sejings arguments.

@extract_sejings('cache')
def add(*nums, cache=sejings.cache):
    result = sum(nums)
    
    if cache(): # True
        save_to_cache(result, cache.path()) #'/some/dir/path'
    
    return result

@TODO

• Context manager
• getitem, setitem