The *conversion* field causes a type coercion before formatting. Normally, the

job of formatting a value is done by the:meth:`__format__` method of the value

job of formatting a value is done by the:meth:`~object.__format__` method of the value

itself. However, in some cases it is desirable to force a type to be formatted

as a string, overriding its own definition of formatting. By converting the

value to a string before calling:meth:`__format__`, the normal formatting logic

value to a string before calling:meth:`~object.__format__`, the normal formatting logic

is bypassed.

Three conversion flags are currently supported: ``'!s'`` which calls:func:`str`