mousse

Mousse

Collections of my most used functions, classes and patterns. I was craving for a delicious mousse as I was comming up with the name.

Installation

pip install -U mousse

Components

Dataclass

This is a self-implement, minimal version of pydantic, with some minor changes.

from typing import *
from mousse import Dataclass, asdict, asclass, Field

class Foo(Dataclass):
    name: str
    number: float
    items: List[str] = []


class Bar(Dataclass):
    foo: Foo
    index: int = Field(..., alias="id")


foo = Foo(
    name="foo", 
    number=42.0, 
    items=["banana", "egg"]
)
bar = Bar(id=1, foo=foo)
print(bar.foo)
# Foo(name="foo", number=42.0, items=['banana', 'egg'])

#convert back to dictionary
bar_dict = asdict(bar)
print(bar_dict)
# {'foo': {'name': 'foo', 'number': 42.0, 'items': ['banana', 'egg']}, 'id': 1}

#conver back to dataclass
bar = asclass(Bar, bar_dict)
print(bar)
# Bar(foo=Foo(name="foo", number=42.0, items=['banana', 'egg']), index=1)

# load from file (.json, .yaml)
bar = asclass(Bar, path="bar.json")
print(bar)
# Bar(foo=Foo(name="foo", number=42.0, items=['banana', 'egg']), index=1)

Some helper functions are:

• validate: Check data type of variable

from typing import *
from mousse import validate, Dataclass

class Foo(Dataclass):
    name: str
    number: float
    items: List[str] = []

Number = Union[int, float]

validate(int, 1) # True
validate(int, 1.0) # False

validate(Number, 1) # True
validate(Number, 1.0) # True

validate(Dict[str, Any], {
    "a": 1,
    "b": "a"
}) # True

validate(Dict[str, int], {
    "a": 1,
    "b": "a"
}) # False

validate(Tuple[int, float], (1, 1.2)) # True
validate(Tuple[int, float], (1.0, 1.2)) # False
validate(Tuple[Number, Number], (1, 1.2)) # True

foo = Foo(
    name="foo", 
    number=42.0, 
    items=["banana", "egg"]
)
validate(Foo, foo) # True
validate(List[Foo], [foo]) # True
validate(List[Foo], (foo,)) # False
validate(Sequence[Foo], (foo,)) # True

• parse: Attempt to parse data

from typing import *
from mousse import parse, Dataclass

class Foo(Dataclass):
    name: str
    number: float
    items: List[str] = []

parse(float, 1) # 1.0
parse(Union[int, float], 1) # 1
parse(Union[float, int], 1) # 1.0

parse(Dict[str, Any], {
    1: 2,
    2: 3
}) # {'1': 2, '2': 3}

parse(Dict[str, float], {
    1: 2,
    2: 3
}) # {'1': 2.0, '2': 3.0}

parse(Foo, {
    "name": "foo",
    "number": 42.2,
    "items": [1, 2, 3]
}) # Foo(name="foo", number=42.2, items=['1', '2', '3'])

Config

This is how I manage the configuration of my application. By creating a Config object that can be loaded once and refered everywhere. Of course, by default, the Config object cannot be changed by convention means. A changing config during runtime is evil.

# entry_point.py

from mousse import load_config

load_config(
    "foo", # to identified a key for the configuration,
    path="config.yaml" # also support json
)

# config.yaml
# foo:
#   name: foo
#   number: 42.0
#   items:
#     - name: banana
#       price: 12
#     - name: egg
#       price: 10
# id: 1

# anywhere.py

from typing import *
from mousse import get_config, asdict, asclass, Dataclass

# This can be called anytime
config = get_config("foo")

# before load_config
print(config)
# Config()

# after load_config
print(config)
# Config(foo=Config(items=[Config(price=12), Config(price=10)]), id=1)

print(config.foo)
# Config(items=[Config(price=12), Config(price=10)])

print(config.foo.items[0].price)
# 12

# reassignment is forbidden 
config.foo = "bar"
# AssertionError: Permission denied

# compatible with asdict
config_data = asdict(config)
print(config_data)
# {
#     "foo": {
#         "name": "foo",
#         "number": 42.0,
#         "items": [
#             {
#                 "name": "banana",
#                 "price": 12
#             },
#             {
#                 "name": "egg",
#                 "price": 10
#             }
#         ]
#     },
#     "id": 1
# }

class Item(Dataclass):
    name: str
    price: int

class Foo(Dataclass):
    name: str
    number: float
    items: List[Item]


class Bar(Dataclass):
    foo: Foo
    id: int


# compatible with asclass
bar = asclass(Bar, config)
print(bar)
# Bar(foo=Foo(name="foo", number=42.0, items=[Item(name="banana", price=12), Item(name="egg", price=10)]), id=1)

Logger

This module is for managing logging process, with pre-defined logging format and both file logging and stdout logging.

# entry_point.py

from mousse import get_logger

logger = get_logger(
    "foo", # key to identify logger,
)
logger.add_handler("RotatingFileHandler", path="logs/foo.out")

# anywhere.py

from mousse import get_logger

logger = get_logger("foo")
logger.info("This is", "my", "logger number:", 1)
# [2022-05-09 20:28:04] [43050 4345906560] [INFO] [anywhere:.<module>:1] This is my logger number: 1

The format of the log is:

[{date} {time}] [{process_id} {thread_id}] [{level}] [{file}:{caller}:{lineno}] {msg}

Pattern

A collection of my most used design patterns

Registry pattern

# registry.py
from mousse import Registry

pokedex = Registry()


class Pokemon:
    def __init__(self, name:str):
        self.name = name

# kanto.py
from .registry import pokedex, Pokemon


@pokedex.register
class Pikachu(Pokemon):
    def sound(self):
        return "pika pika chu"



@pokedex.register
class Charmander(Pokemon):
    def sound(self):
        return "charman charman der"

# johto.py
from .registry import pokedex, Pokemon


@pokedex.register
class Chikorita(Pokemon):
    def sound(self):
        return "chiko chiko"

from . import kanto, johto
from .registry import pokedex


pikachu = pokedex("Pikachu", "1st")
print(pikachu.name, pikachu.sound())

charmander = pokedex("Charmander", "2nd")
print(charmander.name, charmander.sound())

chikorita = pokedex("Chikorita", "3rd")
print(chikorita.name, chikorita.sound())