team-10/env/Lib/site-packages/altair/expr/core.py
2025-08-02 07:34:44 +02:00

282 lines
8.1 KiB
Python

from __future__ import annotations
import datetime as dt
from typing import TYPE_CHECKING, Any, Literal, Union
from altair.utils import SchemaBase
if TYPE_CHECKING:
import sys
from altair.vegalite.v5.schema._typing import Map, PrimitiveValue_T
if sys.version_info >= (3, 10):
from typing import TypeAlias
else:
from typing_extensions import TypeAlias
class DatumType:
"""An object to assist in building Vega-Lite Expressions."""
def __repr__(self) -> str:
return "datum"
def __getattr__(self, attr) -> GetAttrExpression:
if attr.startswith("__") and attr.endswith("__"):
raise AttributeError(attr)
return GetAttrExpression("datum", attr)
def __getitem__(self, attr) -> GetItemExpression:
return GetItemExpression("datum", attr)
def __call__(self, datum, **kwargs) -> dict[str, Any]:
"""Specify a datum for use in an encoding."""
return dict(datum=datum, **kwargs)
datum = DatumType()
def _js_repr(val) -> str:
"""Return a javascript-safe string representation of val."""
if val is True:
return "true"
elif val is False:
return "false"
elif val is None:
return "null"
elif isinstance(val, OperatorMixin):
return val._to_expr()
elif isinstance(val, dt.date):
return _from_date_datetime(val)
else:
return repr(val)
def _from_date_datetime(obj: dt.date | dt.datetime, /) -> str:
"""
Parse native `datetime.(date|datetime)` into a `datetime expression`_ string.
**Month is 0-based**
.. _datetime expression:
https://vega.github.io/vega/docs/expressions/#datetime
"""
fn_name: Literal["datetime", "utc"] = "datetime"
args: tuple[int, ...] = obj.year, obj.month - 1, obj.day
if isinstance(obj, dt.datetime):
if tzinfo := obj.tzinfo:
if tzinfo is dt.timezone.utc:
fn_name = "utc"
else:
msg = (
f"Unsupported timezone {tzinfo!r}.\n"
"Only `'UTC'` or naive (local) datetimes are permitted.\n"
"See https://altair-viz.github.io/user_guide/generated/core/altair.DateTime.html"
)
raise TypeError(msg)
us = obj.microsecond
ms = us if us == 0 else us // 1_000
args = *args, obj.hour, obj.minute, obj.second, ms
return FunctionExpression(fn_name, args)._to_expr()
# Designed to work with Expression and VariableParameter
class OperatorMixin:
def _to_expr(self) -> str:
return repr(self)
def _from_expr(self, expr) -> Any:
return expr
def __add__(self, other):
comp_value = BinaryExpression("+", self, other)
return self._from_expr(comp_value)
def __radd__(self, other):
comp_value = BinaryExpression("+", other, self)
return self._from_expr(comp_value)
def __sub__(self, other):
comp_value = BinaryExpression("-", self, other)
return self._from_expr(comp_value)
def __rsub__(self, other):
comp_value = BinaryExpression("-", other, self)
return self._from_expr(comp_value)
def __mul__(self, other):
comp_value = BinaryExpression("*", self, other)
return self._from_expr(comp_value)
def __rmul__(self, other):
comp_value = BinaryExpression("*", other, self)
return self._from_expr(comp_value)
def __truediv__(self, other):
comp_value = BinaryExpression("/", self, other)
return self._from_expr(comp_value)
def __rtruediv__(self, other):
comp_value = BinaryExpression("/", other, self)
return self._from_expr(comp_value)
__div__ = __truediv__
__rdiv__ = __rtruediv__
def __mod__(self, other):
comp_value = BinaryExpression("%", self, other)
return self._from_expr(comp_value)
def __rmod__(self, other):
comp_value = BinaryExpression("%", other, self)
return self._from_expr(comp_value)
def __pow__(self, other):
# "**" Javascript operator is not supported in all browsers
comp_value = FunctionExpression("pow", (self, other))
return self._from_expr(comp_value)
def __rpow__(self, other):
# "**" Javascript operator is not supported in all browsers
comp_value = FunctionExpression("pow", (other, self))
return self._from_expr(comp_value)
def __neg__(self):
comp_value = UnaryExpression("-", self)
return self._from_expr(comp_value)
def __pos__(self):
comp_value = UnaryExpression("+", self)
return self._from_expr(comp_value)
# comparison operators
def __eq__(self, other):
comp_value = BinaryExpression("===", self, other)
return self._from_expr(comp_value)
def __ne__(self, other):
comp_value = BinaryExpression("!==", self, other)
return self._from_expr(comp_value)
def __gt__(self, other):
comp_value = BinaryExpression(">", self, other)
return self._from_expr(comp_value)
def __lt__(self, other):
comp_value = BinaryExpression("<", self, other)
return self._from_expr(comp_value)
def __ge__(self, other):
comp_value = BinaryExpression(">=", self, other)
return self._from_expr(comp_value)
def __le__(self, other):
comp_value = BinaryExpression("<=", self, other)
return self._from_expr(comp_value)
def __abs__(self):
comp_value = FunctionExpression("abs", (self,))
return self._from_expr(comp_value)
# logical operators
def __and__(self, other):
comp_value = BinaryExpression("&&", self, other)
return self._from_expr(comp_value)
def __rand__(self, other):
comp_value = BinaryExpression("&&", other, self)
return self._from_expr(comp_value)
def __or__(self, other):
comp_value = BinaryExpression("||", self, other)
return self._from_expr(comp_value)
def __ror__(self, other):
comp_value = BinaryExpression("||", other, self)
return self._from_expr(comp_value)
def __invert__(self):
comp_value = UnaryExpression("!", self)
return self._from_expr(comp_value)
class Expression(OperatorMixin, SchemaBase):
"""
Expression.
Base object for enabling build-up of Javascript expressions using
a Python syntax. Calling ``repr(obj)`` will return a Javascript
representation of the object and the operations it encodes.
"""
_schema = {"type": "string"}
def to_dict(self, *args, **kwargs):
return repr(self)
def __setattr__(self, attr, val) -> None:
# We don't need the setattr magic defined in SchemaBase
return object.__setattr__(self, attr, val)
# item access
def __getitem__(self, val):
return GetItemExpression(self, val)
class UnaryExpression(Expression):
def __init__(self, op, val) -> None:
super().__init__(op=op, val=val)
def __repr__(self):
return f"({self.op}{_js_repr(self.val)})"
class BinaryExpression(Expression):
def __init__(self, op, lhs, rhs) -> None:
super().__init__(op=op, lhs=lhs, rhs=rhs)
def __repr__(self):
return f"({_js_repr(self.lhs)} {self.op} {_js_repr(self.rhs)})"
class FunctionExpression(Expression):
def __init__(self, name, args) -> None:
super().__init__(name=name, args=args)
def __repr__(self):
args = ",".join(_js_repr(arg) for arg in self.args)
return f"{self.name}({args})"
class ConstExpression(Expression):
def __init__(self, name) -> None:
super().__init__(name=name)
def __repr__(self) -> str:
return str(self.name)
class GetAttrExpression(Expression):
def __init__(self, group, name) -> None:
super().__init__(group=group, name=name)
def __repr__(self):
return f"{self.group}.{self.name}"
class GetItemExpression(Expression):
def __init__(self, group, name) -> None:
super().__init__(group=group, name=name)
def __repr__(self) -> str:
return f"{self.group}[{self.name!r}]"
IntoExpression: TypeAlias = Union[
"PrimitiveValue_T", dt.date, dt.datetime, OperatorMixin, "Map"
]