dramaticlly commented on a change in pull request #4262: URL: https://github.com/apache/iceberg/pull/4262#discussion_r830520367
########## File path: python/src/iceberg/expression/literals.py ########## @@ -0,0 +1,618 @@ +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, +# software distributed under the License is distributed on an +# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +# KIND, either express or implied. See the License for the +# specific language governing permissions and limitations +# under the License. + +import datetime +import sys +import uuid +from decimal import ROUND_HALF_UP, Decimal +from functools import singledispatch +from typing import Any + +from iceberg.types import PrimitiveType + +if sys.version_info >= (3, 8): + from functools import singledispatchmethod # pragma: no cover +else: + from singledispatch import singledispatchmethod # pragma: no cover + +import pytz + +from iceberg.types import ( + BinaryType, + BooleanType, + DateType, + DecimalType, + DoubleType, + FixedType, + FloatType, + IntegerType, + LongType, + Singleton, + StringType, + TimestampType, + TimestamptzType, + TimeType, + UUIDType, +) + +EPOCH = datetime.datetime.utcfromtimestamp(0) + +""" +Iceberg literal is wrapper class used in expressions, which return unbound predicates +It's being organized as below +Literal +|-- AboveMax +|-- BelowMin +|-- BaseLiteral + |-- FixedLiteral + |-- BinaryLiteral + |-- ComparableLiteral + |-- BooleanLiteral + |-- IntegerLiteral + |-- LongLiteral + |-- FloatLiteral + |-- DoubleLiteral + |-- DateLiteral + |-- StringLiteral + |-- TimeLiteral + |-- TimestampLiteral + |-- DecimalLiteral + |-- UUIDLiteral +""" + + +class Literal: + def to(self, type_var: PrimitiveType): + raise NotImplementedError() + + +class BaseLiteral(Literal): + """Base literal which has a value and can be converted between types""" + + def __init__(self, repr_string: str, value): + self._repr_string = repr_string + if value is None: + raise TypeError("Cannot set value of BaseLiteral to None") + self._value = value + + def to(self, type_var): + raise NotImplementedError() + + @property + def value(self): + return self._value + + def __repr__(self): + return self._repr_string + + def __str__(self): + return str(self._value) + + +@singledispatch +def literal(value: Any) -> BaseLiteral: + """ + A generic Literal factory to construct an iceberg Literal based on python primitive data type + using dynamic overloading + + Args: + value(python primitive type): the value to be associated with literal + + Example: + from iceberg.expressions.literals import literal + >>> literal(123) + <IntegerLiteral(123)>v + """ + raise TypeError(f"Unimplemented Type Literal for value: {value}") + + [email protected] +def _(value: bool): + return BooleanLiteral(value) + + [email protected] +def _(value: int): + """ + Upgrade to long if python int is outside the JAVA_MIN_INT and JAVA_MAX_INT + """ + if value < IntegerType.min or value > IntegerType.max: + return LongLiteral(value) + return IntegerLiteral(value) + + [email protected] +def _(value: float): + """ + Upgrade to double if python float is outside the JAVA_MIN_FLOAT and JAVA_MAX_FLOAT + """ + if value < FloatType.min or value > FloatType.max: + return DoubleLiteral(value) + return FloatLiteral(value) + + [email protected] +def _(value: str): + return StringLiteral(value) + + [email protected] +def _(value: uuid.UUID): + return UUIDLiteral(value) + + [email protected] +def _(value: bytes): + return FixedLiteral(value) + + [email protected] +def _(value: bytearray): + return BinaryLiteral(value) + + [email protected] +def _(value: Decimal): + return DecimalLiteral(value) + + +class ComparableLiteral(BaseLiteral): + def __init__(self, repr_string: str, value): + super(ComparableLiteral, self).__init__(repr_string, value) + + def to(self, type_var): + raise NotImplementedError() + + def __eq__(self, other): + return self.value == other.value + + def __ne__(self, other): + return not self.__eq__(other) + + def __lt__(self, other): + return self.value < other.value + + def __gt__(self, other): + return self.value > other.value + + def __le__(self, other): + return self.value <= other.value + + def __ge__(self, other): + return self.value >= other.value + + +class AboveMax(Literal, Singleton): + def value(self): + raise RuntimeError("AboveMax has no value") + + def to(self, type_var): + raise RuntimeError("Cannot change the type of AboveMax") + + def __str__(self): + return "AboveMax" Review comment: Thank you @Fokko , updated to save define `__str__` for both AboveMax and BelowMin -- This is an automated message from the Apache Git Service. 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