modifiable-items-dictionary 2.0.3

Typed and Tested Modifiable Items Dict which allows keys and values to be modified at run time.

modifiable-items-dict

A simple, fast, typed, and tested implementation for a python3.6+ Modifiable Items dictionary. ModifiableItemsDict extends dict with the ability to modify key's and value's on creation, insertion, and retrieval. This class extends and maintains the original functionality of the builtin dict.

Key Features:

• Easy: Flexable and easy to add Key and/or Value modifiers to the ModifiableItemsDict
• Great Developer Experience: Being fully typed makes it great for editor support.
• Fully Tested: Our test suit fully tests the functionality to ensure that ModifiableItemsDict runs as expected.
• There is More!!!:
  • CaselessDict: CaselessDict extends ModifiableItemsDict which is a CaselessDict which ignores the case of the keys.

Installation

pip install modifiable-items-dictionary

Simple Example

from modifiable_items_dictionary import ModifiableItemsDict


def _add_1(_value):
    if isinstance(_value, int):
        _value += 1
    return _value


def _case_fold_string(_value):
    if isinstance(_value, str):
        _value = _value.casefold()
    return _value


ModifiableItemsDict._key_modifiers = [str.casefold]
ModifiableItemsDict._value_modifiers = (
    _add_1, _case_fold_string)
# Or
# ModifiableItemsDict._key_modifiers = staticmethod(str.casefold)
# ModifiableItemsDict._value_modifiers = [_case_fold_string, _add_1]

modifiable_items_dictionary = ModifiableItemsDict(
    {"lower": 1, "UPPER": 2},
    CamelCase=3,
    snake_case="FoUR"
)

print(
    modifiable_items_dictionary
)  # {'lower': 2, 'upper': 3, 'camelcase': 4, 'snake_case': 'four'}

del modifiable_items_dictionary["LOWER"]
del modifiable_items_dictionary["UPPER"]
modifiable_items_dictionary.pop("SNAKE_CAse")

modifiable_items_dictionary["HeLLO"] = 5

print(modifiable_items_dictionary)  # {'camelcase': 4, 'hello': 6}

Example

Let's say that there is a .json file that has Url hosts and their IP address. Our Goal is to load the json data into a dictionary like structure that will have it's items modified during creation, insertion, and retrieval. This example highlights how to inherit from ModifiableItemsDict and had key and value modifiers.

import ipaddress

from modifiable_items_dictionary import ModifiableItemsDict


class HostDict(ModifiableItemsDict):
    _key_modifiers = [str.casefold, str.strip]
    _value_modifiers = [ipaddress.ip_address]
    # Or
    # _value_modifiers = @staticmethod(ipaddress.ip_address)


browsers = HostDict(
    {
        "  GooGle.com    ": "142.250.69.206",
        " duckDUCKGo.cOM   ": "52.250.42.157",
    }
)

print(browsers)
# {'google.com': IPv4Address('142.250.69.206'), 'duckduckgo.com': IPv4Address('52.250.42.157')}

_old_browser = browsers.pop("  gOOgle.com  ")
# or 
# del host_dict["   GooGle.com  "]

browsers["   BrAvE.com   "] = "2600:9000:234c:5a00:6:d0d2:780:93a1"

print(browsers)
# {'duckduckgo.com': IPv4Address('52.250.42.157'), 'brave.com': IPv6Address('2600:9000:234c:5a00:6:d0d2:780:93a1')}

Threading Example

It is easy to add Threading to a ModifiableItemsDict.

NOTE: Since ModifiableItemsDict is not pickable it does not work with Multiprocessing. It only works with Multithreading.

import multiprocessing.pool
import string
import time

from modifiable_items_dictionary import ModifiableItemsDict

pool = multiprocessing.pool.ThreadPool(10)


def _slow_function(x):
    time.sleep(.05)
    return x


class TimeDictWithThreading(ModifiableItemsDict):
    _key_modifiers = (_slow_function,)
    _value_modifiers = (_slow_function,)
    _map_function = pool.imap_unordered
    # or if order matters
    # _map_function = pool.imap


class TimeDict(ModifiableItemsDict):
    _key_modifiers = (_slow_function,)
    _value_modifiers = (_slow_function,)


iterable = {_letter: _index for _index, _letter in
            enumerate(string.ascii_letters)}

# Without Threading
start = time.perf_counter()
TimeDict(iterable)
end = time.perf_counter()
print(f"{end - start:.2f} seconds")  # 5.54 seconds

# With Threading
start = time.perf_counter()
TimeDictWithThreading(iterable)
end = time.perf_counter()
print(f"{end - start:.2f} seconds")  # 0.64 seconds

Reference

This project was inspired by Raymond Hettinger (rhettinger).

• Hettinger, R. (2023). (Advanced) Python For Engineers: Part 3.