#!/usr/bin/env python
# -*- coding: latin-1 -*-
#
# HOFT utils.
# @module hoft.core.utils
# @version 0.1
# @copyright (c) 2017-present Francis Horsman.
from collections import namedtuple
PositionalError = namedtuple('PositionalError', (
'error', 'name', 'index', 'value', 'func_name', 'func')
)
KeywordError = namedtuple('KeywordError', (
'error', 'name', 'value', 'default_value', 'func_name', 'func')
)
NotAnalysedError = namedtuple('NotAnalysedError', (
'error', 'name', 'argspec', 'callargs')
)
Signature = namedtuple(
'Signature', ('args', 'vaargs', 'kwargs', 'keywords')
)
"""
A Signature representing a parsed argspec for a function:
:param list args: The positional argument names.
:param Union[string|None] vaargs: The positional varargs name (eg after a `*`).
:param dict kwargs: The keyword argument names and associated default values.
:param Union[string|None] keywords: The keyword varkwargs name (eg: after a `**`).
**Example**:
def func(a, b, c=1, \**d) === Signature(['a', 'b'], None, {'c': 1}, 'd')
"""
IGNORE = None
"""
Use this to tell hoft to ignore a function argument when analysing it.
"""
NOVALUE = object()
"""
A special value to indicate that no value was passed to the function for a keyword argument.
"""
__all__ = [
'IGNORE',
'NOVALUE',
'ArgsNotAnalysedError',
'NoDefaultError',
]
[docs]class ArgsNotAnalysedError(Exception):
"""
One or more arguments were not analysed (when `strict=True`).
"""
[docs] def __init__(self, names):
"""
:param List[str] names:
Arguments not analysed (in declared order).
"""
super(ArgsNotAnalysedError, self).__init__(
'ArgsNotAnalysedError: {names}'.format(names=names)
)
self.names = names
[docs]class NoDefaultError(Exception):
"""
No default value is provided for this argument.
"""
[docs] def __init__(self, name, argspec):
"""
:param str name:
Name of the argument
:param inspect.ArgSpec argspec:
Existing argspec.
"""
super(NoDefaultError, self).__init__(
'no default value for positional: {k}'.format(k=name))
self.name = name
self.argspec = argspec
def get_func_name(func):
try:
return func.func_name
except Exception: # NOQA
# Unable to determine target function validator:
return None
def raise_exc(exc, on_error=None, errors=None, fail_fast=False, force=False):
if fail_fast or force:
if on_error is not None:
if isinstance(on_error, Exception):
# Raise the custom exception if required:
raise on_error(exc, errors)
elif callable(on_error):
# Call the user-defined function as required, it is up to it to raise an exception.
on_error(exc, errors)
else:
# Add the errors to the exception and raise it:
exc._errors_ = errors
raise exc
def conditionally_raise_exc(exc, on_error=None, errors=None, fail_fast=False):
raise_exc(
exc=exc,
on_error=on_error,
errors=errors,
fail_fast=fail_fast,
force=False,
)
