aea.helpers.base

Miscellaneous helpers.

locate

locate(path: str) -> Any

Locate an object by name or dotted save_path, importing as necessary.

load_module

load_module(dotted_path: str, filepath: Path) -> types.ModuleType

Load a module.

Arguments:

• dotted_path: the dotted save_path of the package/module.
• filepath: the file to the package/module.

Returns:

module type

Raises:

• ValueError: if the filepath provided is not a module. # noqa: DAR402
• Exception: if the execution of the module raises exception. # noqa: DAR402

load_env_file

load_env_file(env_file: str) -> None

Load the content of the environment file into the process environment.

Arguments:

• env_file: save_path to the env file.

sigint_crossplatform

sigint_crossplatform(process: subprocess.Popen) -> None

Send a SIGINT, cross-platform.

The reason is because the subprocess module doesn't have an API to send a SIGINT-like signal both on Posix and Windows with a single method.

However, a subprocess.Popen class has the method 'send_signal' that gives more flexibility in this terms.

Arguments:

• process: the process to send the signal to.

win_popen_kwargs

win_popen_kwargs() -> dict

Return kwargs to start a process in windows with new process group.

Help to handle ctrl c properly. Return empty dict if platform is not win32

Returns:

windows popen kwargs

send_control_c

send_control_c(process: subprocess.Popen, kill_group: bool = False) -> None

Send ctrl-C cross-platform to terminate a subprocess.

Arguments:

• process: the process to send the signal to.
• kill_group: whether or not to kill group

RegexConstrainedString Objects

class RegexConstrainedString(UserString)

A string that is constrained by a regex.

The default behaviour is to match anything. Subclass this class and change the 'REGEX' class attribute to implement a different behaviour.

__init__

 | __init__(seq: Union[UserString, str]) -> None

Initialize a regex constrained string.

SimpleId Objects

class SimpleId(RegexConstrainedString)

A simple identifier.

The allowed strings are all the strings that: - have at least length 1 - have at most length 128 - the first character must be between a-z,A-Z or underscore - the other characters must be either the above or digits.

Examples of allowed strings:

SimpleId("an_identifier") 'an_identifier'

Examples of not allowed strings:

SimpleId("0an_identifier") Traceback (most recent call last): ... ValueError: Value 0an_identifier does not match the regular expression re.compile('[a-zA-Z_][a-zA-Z0-9_]{0,127}')

SimpleId("an identifier") Traceback (most recent call last): ... ValueError: Value an identifier does not match the regular expression re.compile('[a-zA-Z_][a-zA-Z0-9_]{0,127}')

SimpleId("") Traceback (most recent call last): ... ValueError: Value does not match the regular expression re.compile('[a-zA-Z_][a-zA-Z0-9_]{0,127}')

cd

@contextlib.contextmanager
cd(path: PathLike) -> Generator

Change working directory temporarily.

get_logger_method

get_logger_method(fn: Callable, logger_method: Union[str, Callable]) -> Callable

Get logger method for function.

Get logger in fn definition module or creates logger is module.name. Or return logger_method if it's callable.

Arguments:

• fn: function to get logger for.
• logger_method: logger name or callable.

Returns:

callable to write log with

try_decorator

try_decorator(error_message: str, default_return: Callable = None, logger_method: Any = "error") -> Callable

Run function, log and return default value on exception.

Does not support async or coroutines!

Arguments:

• error_message: message template with one {} for exception
• default_return: value to return on exception, by default None
• logger_method: name of the logger method or callable to print logs

Returns:

the callable

MaxRetriesError Objects

class MaxRetriesError(Exception)

Exception for retry decorator.

retry_decorator

retry_decorator(number_of_retries: int, error_message: str, delay: float = 0, logger_method: str = "error") -> Callable

Run function with several attempts.

Does not support async or coroutines!

Arguments:

• number_of_retries: amount of attempts
• error_message: message template with one {} for exception
• delay: number of seconds to sleep between retries. default 0
• logger_method: name of the logger method or callable to print logs

Returns:

the callable

exception_log_and_reraise

@contextlib.contextmanager
exception_log_and_reraise(log_method: Callable, message: str) -> Generator

Run code in context to log and re raise exception.

Arguments:

• log_method: function to print log
• message: message template to add error text. :yield: the generator

recursive_update

recursive_update(to_update: Dict, new_values: Dict, allow_new_values: bool = False) -> None

Update a dictionary by replacing conflicts with the new values.

It does side-effects to the first dictionary.

to_update = dict(a=1, b=2, subdict=dict(subfield1=1)) new_values = dict(b=3, subdict=dict(subfield1=2)) recursive_update(to_update, new_values) to_update {'a': 1, 'b': 3, 'subdict': {'subfield1': 2}}

Arguments:

• to_update: the dictionary to update.
• new_values: the dictionary of new values to replace.
• allow_new_values: whether or not to allow new values.

find_topological_order

find_topological_order(adjacency_list: Dict[T, Set[T]]) -> List[T]

Compute the topological order of a graph (using Kahn's algorithm).

Arguments:

• adjacency_list: the adjacency list of the graph.

Returns:

the topological order for the graph (as a sequence of nodes)

Raises:

• ValueError: if the graph contains a cycle.

reachable_nodes

reachable_nodes(adjacency_list: Dict[T, Set[T]], starting_nodes: Set[T]) -> Dict[T, Set[T]]

Find the reachable subgraph induced by a set of starting nodes.

Arguments:

• adjacency_list: the adjacency list of the full graph.
• starting_nodes: the starting nodes of the new graph.

Returns:

the adjacency list of the subgraph.

cached_property Objects

class cached_property()

Cached property from python3.8 functools.

__init__

 | __init__(func: Callable) -> None

Init cached property.

__set_name__

 | __set_name__(_: Any, name: Any) -> None

Set name.

__get__

 | __get__(instance: Any, _: Optional[Any] = None) -> Any

Get instance.

ensure_dir

ensure_dir(dir_path: str) -> None

Check if dir_path is a directory or create it.

dict_to_path_value

dict_to_path_value(data: Mapping, path: Optional[List] = None) -> Iterable[Tuple[List[str], Any]]

Convert dict to sequence of terminal path build of keys and value.

parse_datetime_from_str

parse_datetime_from_str(date_string: str) -> datetime.datetime

Parse datetime from string.

CertRequest Objects

class CertRequest()

Certificate request for proof of representation.

__init__

 | __init__(public_key: str, identifier: SimpleIdOrStr, ledger_id: SimpleIdOrStr, not_before: str, not_after: str, message_format: str, save_path: str) -> None

Initialize the certificate request.

Arguments:

• public_key: the public key, or the key id.
• identifier: certificate identifier.
• ledger_id: ledger identifier the request is referring to.
• not_before: specify the lower bound for certificate validity. If it is a string, it must follow the format: 'YYYY-MM-DD'. It will be interpreted as timezone UTC-0.
• not_after: specify the lower bound for certificate validity. If it is a string, it must follow the format: 'YYYY-MM-DD'. It will be interpreted as timezone UTC-0.
• message_format: message format used for signing
• save_path: the save_path where to save the certificate.

public_key

 | @property
 | public_key() -> Optional[str]

Get the public key.

ledger_id

 | @property
 | ledger_id() -> str

Get the ledger id.

key_identifier

 | @property
 | key_identifier() -> Optional[str]

Get the key identifier.

identifier

 | @property
 | identifier() -> str

Get the identifier.

not_before_string

 | @property
 | not_before_string() -> str

Get the not_before field as string.

not_after_string

 | @property
 | not_after_string() -> str

Get the not_after field as string.

not_before

 | @property
 | not_before() -> datetime.datetime

Get the not_before field.

not_after

 | @property
 | not_after() -> datetime.datetime

Get the not_after field.

message_format

 | @property
 | message_format() -> str

Get the message format.

save_path

 | @property
 | save_path() -> Path

Get the save path for the certificate.

Note: if the path is not absolute, then the actual save path might depend on the context.

Returns:

the save path

get_absolute_save_path

 | get_absolute_save_path(path_prefix: Optional[PathLike] = None) -> Path

Get the absolute save path.

If save_path is an absolute path, then the prefix is ignored. Otherwise, the path prefix is prepended.

Arguments:

• path_prefix: the (absolute) path to prepend to the save path.

Returns:

the actual save path.

public_key_or_identifier

 | @property
 | public_key_or_identifier() -> str

Get the public key or identifier.

get_message

 | get_message(public_key: str) -> bytes

Get the message to sign.

construct_message

 | @classmethod
 | construct_message(cls, public_key: str, identifier: SimpleIdOrStr, not_before_string: str, not_after_string: str, message_format: str) -> bytes

Construct message for singning.

Arguments:

• public_key: the public key
• identifier: identifier to be signed
• not_before_string: signature not valid before
• not_after_string: signature not valid after
• message_format: message format used for signing

Returns:

the message

get_signature

 | get_signature(path_prefix: Optional[PathLike] = None) -> str

Get signature from save_path.

Arguments:

• path_prefix: the path prefix to be prepended to save_path. Defaults to cwd.

Returns:

the signature.

json

 | @property
 | json() -> Dict

Compute the JSON representation.

from_json

 | @classmethod
 | from_json(cls, obj: Dict) -> "CertRequest"

Compute the JSON representation.

__eq__

 | __eq__(other: Any) -> bool

Check equality.

compute_specifier_from_version

compute_specifier_from_version(version: Version) -> str

Compute the specifier set from a version.

version specifier is: >=major.minor.0, <next_major.0.0

Arguments:

• version: the version

Returns:

the specifier set

decorator_with_optional_params

decorator_with_optional_params(decorator: Callable) -> Callable

Make a decorator usable either with or without parameters.

In other words, if a decorator "mydecorator" is decorated with this decorator, It can be used both as:

@mydecorator def myfunction(): ...

or as:

@mydecorator(arg1, kwarg1="value") def myfunction(): ...

Arguments:

• decorator: a decorator callable

Returns:

a decorator callable

delete_directory_contents

delete_directory_contents(directory: Path) -> None

Delete the content of a directory, without deleting it.

prepend_if_not_absolute

prepend_if_not_absolute(path: PathLike, prefix: PathLike) -> PathLike

Prepend a path with a prefix, but only if not absolute

Arguments:

• path: the path to process.
• prefix: the path prefix.

Returns:

the same path if absolute, else the prepended path.