nonebot2/none/expression.py
2018-10-16 01:03:50 +08:00

26 lines
769 B
Python

import random
from typing import Sequence, Callable
from .message import escape
from .typing import Expression_T
def render(expr: Expression_T, *, escape_args: bool = True, **kwargs) -> str:
"""
Render an expression to message string.
:param expr: expression to render
:param escape_args: should escape arguments or not
:param kwargs: keyword arguments used in str.format()
:return: the rendered message
"""
if isinstance(expr, Callable):
expr = expr(**kwargs)
elif isinstance(expr, Sequence) and not isinstance(expr, str):
expr = random.choice(expr)
if escape_args:
for k, v in kwargs.items():
if isinstance(v, str):
kwargs[k] = escape(v)
return expr.format(**kwargs)