#!/usr/bin/env python3
#
# Copyright 2021 Graviti. Licensed under MIT License.
#
"""The implementation of the TensorBay repr."""
from abc import ABC
from enum import Enum, auto
from typing import (
Any,
Callable,
ClassVar,
Dict,
Iterable,
Mapping,
Sequence,
Tuple,
Type,
TypeVar,
Union,
)
[docs]class ReprType(Enum):
"""ReprType is an enumeration type.
It defines the repr strategy type and includes 'INSTANCE', 'SEQUENCE' and 'MAPPING'.
"""
INSTANCE = auto()
SEQUENCE = auto()
MAPPING = auto()
[docs]class ReprMixin:
"""ReprMixin provides customized repr config and method."""
_repr_type: ClassVar[ReprType] = ReprType.INSTANCE
_repr_attrs: Iterable[str] = ()
_repr_maxlevel = 1
_repr_non_empty = False
def __repr__(self) -> str:
return _repr1(self, self._repr_maxlevel, self._repr_maxlevel, True)
def __str__(self) -> str:
return _repr1(self, self._repr_maxlevel, self._repr_maxlevel, False)
def _repr_head(self) -> str:
return self.__class__.__name__
class _ReprConfig:
"""Config for customized repr method.
Arguments:
indent: The indent width for different level repr string.
maxlist: The max items displayed in the sequence repr string.
maxdict: The max items displayed in the mapping repr string.
"""
def __init__(self, indent: int = 2, maxlist: int = 16, maxdict: int = 16) -> None:
self.indent = indent
self.maxlist = maxlist
self.maxdict = maxdict
@property
def indent(self) -> int:
"""The getter of repr indent width.
Returns:
The indent width of repr config.
"""
return self._indent
@indent.setter
def indent(self, indent: int) -> None:
"""The setter of repr indent width.
Arguments:
indent: The width of the ident to be set.
"""
self._indent = indent
self._indent_str = " " * indent
repr_config = _ReprConfig()
# Explicitly inherit from 'abc.ABC' to tell pylint it is a abstract class
# Reference:
# - https://github.com/PyCQA/pylint/issues/3098
# - https://github.com/PyCQA/pylint/pull/3446
class _ReprSequence(ReprMixin, Sequence[Any], ABC):
...
class _ReprMapping(ReprMixin, Mapping[Any, Any], ABC):
...
_ReprPrinter = Callable[[Any, int, int, bool], str]
_PRINTERS: Dict[Union[Type[Any], ReprType], _ReprPrinter] = {}
class _PrinterRegister:
"""Decorator class to register repr printer functions to '_PRINTERS'.
Arguments:
key: The key of the '_PRINTERS' for repr dispatch.
"""
_S = TypeVar("_S", bound=_ReprPrinter)
def __init__(self, key: Union[Type[Any], ReprType]) -> None:
self._key = key
def __call__(self, printer: _S) -> _S:
_PRINTERS[self._key] = printer
return printer
def _repr1(obj: Any, level: int, maxlevel: int, folding: bool) -> str:
"""Customized repr method.
Arguments:
obj: The object need to be transferred to repr string.
level: The current repr level.
maxlevel: The max repr level.
folding: Whether fold the "repr" of the object.
Returns:
"repr" of the object.
"""
class_: Type[Any] = type(obj)
printer = _PRINTERS.get(getattr(class_, "_repr_type", class_), None)
return printer(obj, level, maxlevel, folding) if printer else repr(obj)
@_PrinterRegister(ReprType.INSTANCE)
def _repr_instance(obj: ReprMixin, level: int, maxlevel: int, folding: bool) -> str:
"""Customized repr method for `ReprType.INSTANCE`.
Arguments:
obj: The object need to be transferred to repr string.
level: The current repr level.
maxlevel: The max repr level.
folding: Whether fold the "repr" of the object.
Returns:
"repr" of the object.
"""
# pylint: disable=protected-access
return f"{obj._repr_head()}{_repr_attrs(obj, level, maxlevel, folding)}"
@_PrinterRegister(ReprType.SEQUENCE)
def _repr_sequence(obj: _ReprSequence, level: int, maxlevel: int, folding: bool) -> str:
"""Customized repr method for `ReprType.SEQUENCE`.
Arguments:
obj: The object need to be transferred to repr string.
level: The current repr level.
maxlevel: The max repr level.
folding: Whether fold the "repr" of the object.
Returns:
"repr" of the object.
"""
# pylint: disable=protected-access
return (
f"{obj._repr_head()} {_repr_builtin_list(obj, level, maxlevel, folding)}"
f"{_repr_attrs(obj, level, maxlevel, folding)}"
)
@_PrinterRegister(ReprType.MAPPING)
def _repr_mapping(obj: _ReprMapping, level: int, maxlevel: int, folding: bool) -> str:
"""Customized repr method for `ReprType.MAPPING`.
Arguments:
obj: The object need to be transferred to repr string.
level: The current repr level.
maxlevel: The max repr level.
folding: Whether fold the "repr" of the object.
Returns:
"repr" of the object.
"""
# pylint: disable=protected-access
return (
f"{obj._repr_head()} {_repr_builtin_dict(obj, level, maxlevel, folding)}"
f"{_repr_attrs(obj, level, maxlevel, folding)}"
)
@_PrinterRegister(list)
def _repr_builtin_list(obj: Sequence[Any], level: int, maxlevel: int, folding: bool) -> str:
"""Customized repr method for buildin type list.
Arguments:
obj: The object need to be transferred to repr string.
level: The current repr level.
maxlevel: The max repr level.
folding: Whether fold the "repr" of the object.
Returns:
"repr" of the object.
"""
return _repr_builtin_sequence(obj, level, maxlevel, folding, "[", "]")
@_PrinterRegister(tuple)
def _repr_builtin_tuple(obj: Sequence[Any], level: int, maxlevel: int, folding: bool) -> str:
"""Customized repr method for buildin type tuple.
Arguments:
obj: The object need to be transferred to repr string.
level: The current repr level.
maxlevel: The max repr level.
folding: Whether fold the "repr" of the object.
Returns:
"repr" of the object.
"""
return _repr_builtin_sequence(obj, level, maxlevel, folding, "(", ")")
@_PrinterRegister(dict)
def _repr_builtin_dict(obj: Mapping[Any, Any], level: int, maxlevel: int, folding: bool) -> str:
"""Customized repr method for buildin type dict.
Arguments:
obj: The object need to be transferred to repr string.
level: The current repr level.
maxlevel: The max repr level.
folding: Whether fold the "repr" of the object.
Returns:
"repr" of the object.
"""
if getattr(obj, "_repr_non_empty", False) and level <= 0:
return "{...}"
object_length = len(obj)
if object_length == 0:
return "{}"
if level <= 0:
return "{...}"
newlevel = level - 1
keys = tuple(obj)
fold, unfold = _calculate_fold_number(object_length, repr_config.maxdict, folding)
pieces = [
f"{repr(key)}: {_repr1(obj[key], newlevel, maxlevel, folding)}" for key in keys[:unfold]
]
if fold:
key = keys[-1]
pieces.append(f"... ({fold} items are folded)")
pieces.append(f"{repr(key)}: {_repr1(obj[key], newlevel, maxlevel, folding)}")
return _join_with_indent(pieces, level, maxlevel, "{", "}")
def _repr_attrs(obj: Any, level: int, maxlevel: int, folding: bool) -> str:
"""Customized repr method for object attributes.
Arguments:
obj: The object need to be transferred to repr string.
level: The current repr level.
maxlevel: The max repr level.
folding: Whether fold the "repr" of the object.
Returns:
"repr" of the object.
"""
# pylint: disable=protected-access
if not obj._repr_attrs:
return ""
attributes = []
for attribute in obj._repr_attrs:
value = getattr(obj, attribute, ...)
if value is not ...:
attributes.append((attribute, value))
if not attributes:
return "()"
if level <= 0:
return "(...)"
newlevel = level - 1
pieces = (f"({key}): {_repr1(value, newlevel, maxlevel, folding)}" for key, value in attributes)
return _join_with_indent(pieces, level, maxlevel, "(", ")")
def _repr_builtin_sequence( # pylint: disable=too-many-arguments
obj: Sequence[Any], level: int, maxlevel: int, folding: bool, left: str, right: str
) -> str:
"""Customized repr method for sequence.
Arguments:
obj: The object need to be transferred to repr string.
level: The current repr level.
maxlevel: The max repr level.
folding: Whether fold the "repr" of the object.
left: The left bracket symbol.
right: The right bracket symbol.
Returns:
"repr" of the object.
"""
if getattr(obj, "_repr_non_empty", False) and level <= 0:
return f"{left}...{right}"
object_length = len(obj)
if object_length == 0:
return f"{left}{right}"
if level <= 0:
return f"{left}...{right}"
newlevel = level - 1
fold, unfold = _calculate_fold_number(object_length, repr_config.maxlist, folding)
pieces = [_repr1(item, newlevel, maxlevel, folding) for item in obj[:unfold]]
if fold:
pieces.append(f"... ({fold} items are folded)")
pieces.append(_repr1(obj[-1], newlevel, maxlevel, folding))
return _join_with_indent(pieces, level, maxlevel, left, right)
def _calculate_fold_number(length: int, max_length: int, folding: bool) -> Tuple[int, int]:
"""Calculate the number of the folded and unfolded items.
Arguments:
length: The object length.
max_length: The configured max length.
folding: Whether fold the "repr" of the object.
Returns:
The number of the folded items & the number of the unfolded items.
"""
if folding and length > max_length:
return length - max_length + 1, max_length - 2
return 0, length
def _join_with_indent(
pieces: Iterable[str], level: int, maxlevel: int, left: str, right: str
) -> str:
"""Handle the indent, newline and "," of the string list.
Arguments:
pieces: The string list need to be transferred to repr string.
level: The current repr level.
maxlevel: The max repr level.
left: The left bracket symbol.
right: The right bracket symbol.
Returns:
Repr string with indent, newline and ",".
"""
# pylint: disable=protected-access
inner_indent = repr_config._indent_str * (maxlevel - level + 1)
outer_indent = repr_config._indent_str * (maxlevel - level)
sep = f",\n{inner_indent}"
return f"{left}\n{inner_indent}{sep.join(pieces)}\n{outer_indent}{right}"