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A database interface that acts like a python dictionary

Install

pip install dictabase

Create a new table

# Create a table representing users
from dictabase import BaseTable, RegisterDBURI

RegisterDBURI() # pass nothing to default to sqlite

class UserClass(BaseTable):
    pass

newUser = New(UserClass, name='Grant', age=31)
newUser = New(UserClass, name='Bob', age=99)
# there is now a sqlite database containing the 2 users. Yup, thats it!

Look up items in the database

from dictabase import FindOne, FindAll

allUsers = FindAll(UserClass)
# allUsers is an iterable of all the UserClass objects that exists in the database
print('allUsers=', list(allUsers))
>> allUsers= [<UserClass: name='Grant', age=31>, <UserClass: name='Bob', age=99>]

user = FindOne(UserClass, name='Grant')
print('user=', user)
>>user= <UserClass: name='Grant', age=31>

user = FindOne(UserClass, name='NotARealName')
print('user=', user)
>>user= None

Read/Write to the database

# find an object that was previously put in the database
user = FindOne(UserClass, name='Grant')

# increment the age of the user by 1
user['age'] += 1
# Thats it! the database has now been updated with the new age

Drop a table

from dictabase import Drop
Drop(UserClass, confirm=True)
# the table has been removed from the database

Delete a specific row in a table

from dictabase import Delete
# find an object that was previously put in the database
user = FindOne(UserClass, name='Grant')
Delete(user)
# the user has been removed from the database

Advanced Usage

You can only store simple types like int, str, datetime in the database. To store more complicated objects, like list, dict, or any arbitrary type, override the DumpKey() and LoadKey() method. Using these methods, you can convert complex types into these more simple types.

from dictabase import (
    BaseTable,
    FindOne,
    New,
    RegisterDBURI,
    Drop,
)
import json

RegisterDBURI()


class Page(BaseTable):
    pass


Drop(Page, confirm=True) # clear the table for this test


class Book(BaseTable):
    def DumpKey(self, key, value):
        # this is called when putting info into the database
        if key == 'pages':
            ret = [page['id'] for page in value] # only store the page id as a json'd list of ints
            return json.dumps(ret)
        else:
            return value

    def LoadKey(self, key, value):
        # this is called when extracting info from the database
        if key == 'pages':
            ret = json.loads(value)
            ret = [FindOne(Page, id=ID) for ID in ret]
        else:
            return value


Drop(Book, confirm=True) # clear the table for this test

# Create a new book
book = New(Book)
book['pages'] = [] # this will hold our pages

print('book=', book)
>> book= <Book: id=1(type=int), pages=[](type=list)>

# Fill the book with pages
for i in range(10):
    page = New(
        Page,
        words='These are words {}'.format(i),
        parentBookID=book['id']
    )
    book['pages'].append(page)

print('book=', book)
>> book= <Book: id=1(type=int), pages=[<Page: words=These are words 0(type=str), parentBookID=1(type=int), id=1(type=int)>, <Page: words=These are words 1(type=str), parentBookID=1(type=int), id=2(type=int)>, <Page: words=These are words 2(type=str), parentBookID=1(type=int), id=3(type=int)>, <Page: words=These are words 3(type=str), parentBookID=1(type=int), id=4(type=int)>, <Page: words=These are words 4(type=str), parentBookID=1(type=int), id=5(type=int)>, <Page: words=These are words 5(type=str), parentBookID=1(type=int), id=6(type=int)>, <Page: words=These are words 6(type=str), parentBookID=1(type=int), id=7(type=int)>, <Page: words=These are words 7(type=str), parentBookID=1(type=int), id=8(type=int)>, <Page: words=These are words 8(type=str), parentBookID=1(type=int), id=9(type=int)>, <Page: words=These are words 9(type=str), parentBookID=1(type=int), id=10(type=int)>](type=list)>

# Look up the book/pages in the database
foundBook = FindOne(Book)

print('foundBook=', foundBook)
>> foundBook= <Book: id=1(type=int), pages=[<Page: words=These are words 0(type=str), parentBookID=1(type=int), id=1(type=int)>, <Page: words=These are words 1(type=str), parentBookID=1(type=int), id=2(type=int)>, <Page: words=These are words 2(type=str), parentBookID=1(type=int), id=3(type=int)>, <Page: words=These are words 3(type=str), parentBookID=1(type=int), id=4(type=int)>, <Page: words=These are words 4(type=str), parentBookID=1(type=int), id=5(type=int)>, <Page: words=These are words 5(type=str), parentBookID=1(type=int), id=6(type=int)>, <Page: words=These are words 6(type=str), parentBookID=1(type=int), id=7(type=int)>, <Page: words=These are words 7(type=str), parentBookID=1(type=int), id=8(type=int)>, <Page: words=These are words 8(type=str), parentBookID=1(type=int), id=9(type=int)>, <Page: words=These are words 9(type=str), parentBookID=1(type=int), id=10(type=int)>](type=list)>

for page in foundBook['pages']:
    print('page=', page)
>> page= <Page: words=These are words 0(type=str), parentBookID=1(type=int), id=1(type=int)>
>> page= <Page: words=These are words 1(type=str), parentBookID=1(type=int), id=2(type=int)>
>> page= <Page: words=These are words 2(type=str), parentBookID=1(type=int), id=3(type=int)>
>> page= <Page: words=These are words 3(type=str), parentBookID=1(type=int), id=4(type=int)>
>> page= <Page: words=These are words 4(type=str), parentBookID=1(type=int), id=5(type=int)>
>> page= <Page: words=These are words 5(type=str), parentBookID=1(type=int), id=6(type=int)>
>> page= <Page: words=These are words 6(type=str), parentBookID=1(type=int), id=7(type=int)>
>> page= <Page: words=These are words 7(type=str), parentBookID=1(type=int), id=8(type=int)>
>> page= <Page: words=These are words 8(type=str), parentBookID=1(type=int), id=9(type=int)>
>> page= <Page: words=These are words 9(type=str), parentBookID=1(type=int), id=10(type=int)>