f-string-without-interpolation / W1309

Message emitted:

Using an f-string that does not have any interpolated variables

Description:

Used when we detect an f-string that does not use any interpolation variables, in which case it can be either a normal string or a bug in the code.

Problematic code:

x = 1
y = 2
print(f"x + y = x + y")  # [f-string-without-interpolation]

Correct code:

x = 1
y = 2
print(f"{x} + {y} = {x + y}")

Created by the string checker.