Use f-string type conversion !r in error messages to avoid single quotes

[seisman]

Currently, the error messages are in the following style:

>>> arg = "invalid"
>>> msg = f"Invalid value: '{arg}'."
>>> print(msg)
Invalid value: 'invalid'.

>>> arg = 10
>>> msg = f"Invalid value: '{arg}'."
>>> print(msg)
Invalid value: '10'.

>>> arg = None
>>> msg = f"Invalid value: '{arg}'."
>>> print(msg)
Invalid value: 'None'.

The cons are:

• Extra single quotes in f-strings
• Values are always enclosed in single quotes, regardless of the types

I propose to use type conversion !r in the new style:

>>> arg = "invalid"
>>> msg = f"Invalid value: {arg!r}."
>>> print(msg)
Invalid value: 'invalid'.

>>> arg = 10
>>> msg = f"Invalid value: {arg!r}."
>>> print(msg)
Invalid value: 10.

>>> arg = None
>>> msg = f"Invalid value: {arg!r}."
>>> print(msg)
Invalid value: None.

>>> arg = [10, 20, 30]
>>> msg = f"Invalid value: {arg!r}."
>>> print(msg)
Invalid value: [10, 20, 30].

👍 if you like new style; 👎 if you like the old style; or leave your comments.