angelos.common.utils

Utility module.

The utility module containse all minor extras that is used globally in the application.

class angelos.common.utils.Checksum

Bases: object

Generate and check checksum based on introspection of data stream.

check(sum: bytes) → bool

Compare introspected sum with given sum.

checksum(length: int = 1) → bytes

Generate a checksum of certain byte size.

introspect(stream: Union[bytes, bytearray])

Build checksum based on a stream with multiple data chunks.

class angelos.common.utils.Event(*, loop=None)

Bases: asyncio.locks.Event

A threadsafe asynchronous event class.

set()

Set the internal flag to true. All coroutines waiting for it to become true are awakened. Coroutine that call wait() once the flag is true will not block at all.

class angelos.common.utils.EventState(states: list)

Bases: angelos.common.utils.SingleState

A state machine that triggers an event at state change.

goto(state: unicode)

Go to another state and trigger an event.

wait_for(predicate)

Wait for a state to happen.

class angelos.common.utils.FactoryInterface

Bases: object

Docstring

classmethod factory(**kwargs)

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class angelos.common.utils.MultiState(states: dict)

Bases: angelos.common.utils.StateMachine

A state machine that allows switching between predefined states.

property available

Expose available options.

goto(state: unicode)

Go to another state that is available.

class angelos.common.utils.SingleState(states: tuple)

Bases: angelos.common.utils.StateMachine

A state machine that allows switching between states.

property available

Expose available options.

goto(state: unicode)

Go to another state that is available.

class angelos.common.utils.StateMachine

Bases: object

A class that can hold a single state at a time.

property available

Expose available options.

goto(state: unicode)

Switch to another state.

property state

Get state.

class angelos.common.utils.Util

Bases: object

General basic utilities.

static class_pkg(klass)

Docstring

static generate_checksum(data: Union[bytes, bytearray]) → bytes

Generate a checksum out of the entered data.

static headline(title: unicode, filler: unicode = '', barrier='-')

Print headlines.

static hours(seconds)

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static is_class(instance, types)

check_class is a helper function. Tests for a subclass and raises a standardized TypeError exception.

Instance The instanced variable type The class type of expected type, or tuple of them

Example: check_class(result, (Model, BaseModel))

static is_type(instance, types)

check_type is a helper function. Tests for an instance and raises a standardized TypeError exception.

Instance The instanced variable type The class type of expected type, or tuple of them

Example: check_type(result, (NoneType, StringType))

is_typing(types)

Check instance, even on typing classes.

Instance The instanced variable type The class type of expected type, or tuple of them

static klass(module: unicode, cls: unicode) → Type[Any]

Load a class from a module in a package.

static log_exception(exc: Exception)

Log exception and traceback using the logging.critical() method.

static path(dirname, filename)

Merge directory path and filename.

static populate(klass: object, attributes: dict) → None

Populate class attributes from dictionary.

Parameters

• klass –

• attributes –

static print_exception(exc: Exception)

Print exception and traceback using the python print() method.

static verify_checksum(data: Union[bytes, bytearray], checksum: bytes) → bool

Verify the checksum out of the entered data.