ruff/crates/ty_python_semantic/resources/mdtest/literal/f_string.md

f-strings

Expression

from typing_extensions import Literal

def _(x: Literal[0], y: str, z: Literal[False]):
    reveal_type(f"hello")  # revealed: Literal["hello"]
    reveal_type(f"h {x}")  # revealed: Literal["h 0"]
    reveal_type("one " f"single " f"literal")  # revealed: Literal["one single literal"]
    reveal_type("first " f"second({x})" f" third")  # revealed: Literal["first second(0) third"]
    reveal_type(f"-{y}-")  # revealed: str
    reveal_type(f"-{y}-" f"--" "--")  # revealed: str
    reveal_type(f"{z} == {False} is {True}")  # revealed: Literal["False == False is True"]

Conversion Flags

string = "hello"

# TODO: should be `Literal["'hello'"]`
reveal_type(f"{string!r}")  # revealed: str

Format Specifiers

# TODO: should be `Literal["01"]`
reveal_type(f"{1:02}")  # revealed: str