Saving unit database as JSON file

[jonlym]

Currently, VUnits stores the unit database in its code, which is imported whenever the vunits.db module is accessed. However, prefixes and suffixes are added during the import process, which can slow down the initialization of the database.

One option is to save the database as a JSON file, which will probably load faster and can be updated whenever necessary.

[jonlym]

The following code was run using the old approach and the new approach.

import timeit

'''Code to evaluate'''
code1 = r"""
from vunits.db import unit_db
unit_db['kg']"""


'''Evaluate performance'''
print('Time: {}'.format(min(timeit.repeat(code1, repeat=10))))

The times obtained are as follows.

Approach	Time
Initializing DB when imported (Old Method)	0.892
Loading from JSON file (New Method)	0.711

The new approach shows some speedup but not as significant as I would like. For now, we'll implement the new approach but will still look for more ways to speed up the database initialization process further.

[jonlym]

Fixed in commit 98c8304

[jonlym]

Changed Quantity objects to use dictionaries instead of Dataframes in commit 01fcfcf. Reduced IO time of above script to 0.5050562999999997.