as3ninja/utils.py
# -*- coding: utf-8 -*-
"""
Various utils and helpes used by AS3 Ninja
"""
# pylint: disable=C0330 # Wrong hanging indentation before block
# pylint: disable=C0301 # Line too long
# pylint: disable=C0116 # Missing function or method docstring
import json
import sys
from functools import wraps
from pathlib import Path
from typing import (
Any,
Dict,
ItemsView,
Iterator,
KeysView,
List,
Optional,
Union,
ValuesView,
)
import yaml
class YamlConstructor: # pylint: disable=R0903 # Too few public methods (1/2) (too-few-public-methods)
"""
Organizes functions to implement a custom PyYAML constructor
"""
INCLUDE_TAG = "!include"
@staticmethod
def _path_glob(value: str) -> List[str]:
"""
A Path().glob() helper function, checks if `value` actually contains a globbing pattern and either returns `value` or the result of the globbing.
:param value: String to check for globbing pattern and, if pattern found, to feed to Path().glob()
"""
if "*" in value: # globbing is used
# return list of str with all globbing results
return [str(entry) for entry in Path().glob(value)]
return [value]
@classmethod
def _include_constructor(cls, _, node) -> Union[List, Dict]:
"""
The PyYAML constructor for the INCLUDE_TAG (!include).
This method should not be called directly, it is passed to PyYAML as a constructor function.
:param node: The yaml node to be inspected
"""
yaml_files: List = []
if isinstance(
node, yaml.nodes.ScalarNode
): # single include statement (type str)
yaml_files = cls._path_glob(node.value)
if len(yaml_files) == 1:
# return immediately as Path.glob doesn't resolve to multiple files
with open(yaml_files[0]) as yml_file:
return yaml.safe_load(yml_file)
elif len(yaml_files) == 0:
# _path_glob has not found a single file
raise FileNotFoundError(f"No file found based on node:{node.value}")
elif isinstance(node, yaml.nodes.SequenceNode): # include is of type list
for entry in node.value:
# extend list with globbed entries
yaml_files.extend(cls._path_glob(entry.value))
else:
# yaml.nodes.MappingNode is not supported / nor is any other
raise TypeError(
f"YAML Node of type:{type(node)} is not supported. node:{node}"
)
result = []
for yaml_file in yaml_files:
with open(yaml_file) as yml_file:
result.append(yaml.safe_load(yml_file))
return result
@classmethod
def add_constructors(cls, yaml_module):
"""
Adds constructors to PyYAML module.
:param yaml_module: Name of loaded PyYAML module
"""
yaml_module.add_constructor(
cls.INCLUDE_TAG, cls._include_constructor, Loader=yaml_module.SafeLoader
)
YamlConstructor.add_constructors(yaml)
def deserialize(datasource: str) -> Dict:
"""
deserialize de-serializes JSON or YAML from a file to a python dict.
A ValueError exception is raised if JSON and YAML de-serialization fails.
A FileNotFoundError is raised when an included file is not found.
:param datasource: The filename (including path) to deserialize
"""
with open(datasource, "r") as jy_file:
data = jy_file.read()
try:
_data = json.loads(data)
except (json.JSONDecodeError, TypeError):
try:
_data = yaml.safe_load(data)
except (
yaml.parser.ParserError,
yaml.scanner.ScannerError,
TypeError,
ValueError,
) as yaml_exception:
raise ValueError(
"deserialize: Could not deserialize datasource. datasource is neither valid JSON nor YAML."
) from yaml_exception
except FileNotFoundError as yaml_exception:
raise FileNotFoundError(
"deserialize: Could not deserialize datasource. FileNotFoundError"
) from yaml_exception
return _data
class DictLike:
"""Makes objects `feel` like a dict.
Implements required dunder and common methods used to access dict data.
"""
_dict: dict = {}
def __iter__(self) -> Iterator[str]:
for key in self._dict:
yield key
def __len__(self) -> int:
return len(self._dict)
def __contains__(self, item: Any) -> bool:
return item in self._dict
def __eq__(self, other: Any) -> bool:
return self._dict.items() == other.items()
def __getitem__(self, key: str) -> Any:
return self._dict.__getitem__(key)
def __repr__(self) -> str:
return f"{self.__class__.__name__}({self._dict})"
def __str__(self) -> str:
return str(self._dict)
def get(self, key: Any, default: Any = None) -> Any:
return self._dict.get(key, default)
def keys(self) -> KeysView[Any]:
return self._dict.keys()
def values(self) -> ValuesView[Any]:
return self._dict.values()
def items(self) -> ItemsView[Any, Any]:
return self._dict.items()
def failOnException(wrapped_function):
"""sys.exit(1) on any exception"""
@wraps(wrapped_function)
def failOnException_wrapper(*args, **kwargs):
"""wrapper function"""
try:
return wrapped_function(*args, **kwargs)
except Exception: # pylint: disable=W0703
sys.exit(1)
return failOnException_wrapper
def escape_split(string_to_split: str, seperator: str = ".") -> tuple:
"""Splits a string based on the provided seperator.
escape_split supports escaping the seperator by prepending a backslash.
:param string_to_split: String to split
:param seperator: Seperator to use for splitting (Default: ".")
"""
i, res, buffer = 0, [], ""
while True:
j, e = string_to_split.find(seperator, i), 0
if j < 0:
return tuple(res + [buffer + string_to_split[i:]])
while j - e and string_to_split[j - e - 1] == "\\":
e += 1
d = e // 2
if e != d * 2:
buffer += string_to_split[i : j - d - 1] + string_to_split[j]
i = j + 1
continue
res.append(buffer + string_to_split[i : j - d])
i = j + len(seperator)
buffer = ""
class PathAccessError(KeyError, IndexError, TypeError):
"""An amalgamation of KeyError, IndexError, and TypeError,
representing what can occur when looking up a path in a nested
object.
"""
def __init__(self, exc, seg, path):
self.exc = exc
self.seg = seg
self.path = path
def __repr__(self):
return f"{self.__class__.__name__}({self.exc}, {self.seg}, {self.path})"
def __str__(self):
return (
f"could not access {self.seg} from path {self.path}, got error: {self.exc}"
)
def dict_filter(
dict_to_filter: dict, filter: Optional[Union[tuple, str]] = None
) -> Any:
"""Filters a dict based on the provided filter.
dict_filter will walk the dict keys based on the filter and will return the value of the last key.
If filter is empty, dict_to_filter will be returned.
Example:
assert dict_filter({ 'a': { 'b': [1,2,3] } }, filter="a.b") == [1,2,3]
:param dict_to_filter: Python dict to filter
:param filter: Filter to apply to the dict. Filter can be a ``str`` (will be split on `.`) or a ``tuple``.
"""
if filter:
if isinstance(filter, str):
filter = escape_split(filter)
for seg in filter:
try:
dict_to_filter = dict_to_filter[seg]
except (KeyError, IndexError) as exc:
raise PathAccessError(exc, seg, filter)
except TypeError as exc:
# either string index in a list, or a parent that
# doesn't support indexing
try:
seg = int(seg)
dict_to_filter = dict_to_filter[seg]
except (ValueError, KeyError, IndexError, TypeError):
try:
iter(dict_to_filter)
except TypeError:
exc = TypeError(
f"{type(dict_to_filter).__name__} object is not indexable"
)
raise PathAccessError(exc, seg, filter)
return dict_to_filter
# pylint: disable=W0105 # String statement has no effect
"""
PathAccessError and dict_filter are based on boltons iterutils: https://github.com/mahmoud/boltons
boltons license:
Copyright (c) 2013, Mahmoud Hashemi
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following
disclaimer in the documentation and/or other materials provided
with the distribution.
* The names of the contributors may not be used to endorse or
promote products derived from this software without specific
prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
"""