Method push_format_context

src/_pytest/assertion/rewrite.py:806–817

Create a new formatting context. The format context is used for when an explanation wants to have a variable value formatted in the assertion message. In this case the value required can be added using .explanation_param(). Finally .pop_format_context() is used

(self)

        return "%(" + specifier + ")s"

    def push_format_context(self) -> None:
        """Create a new formatting context.

        The format context is used for when an explanation wants to
        have a variable value formatted in the assertion message.  In
        this case the value required can be added using
        .explanation_param().  Finally .pop_format_context() is used
        to format a string of %-formatted values as added by
        .explanation_param().
        """
        self.explanation_specifiers: dict[str, ast.expr] = {}
        self.stack.append(self.explanation_specifiers)

    def pop_format_context(self, expl_expr: ast.expr) -> ast.Name:
        """Format the %-formatted string with current format context.