Function _template_to_ast

Lib/annotationlib.py:630–648

Make a best-effort conversion of a `template` instance to an AST.

(template)

def _template_to_ast(template):
    """Make a best-effort conversion of a `template` instance to an AST."""
    # gh-138558: Not all Template instances can be represented as t-string
    # literals. Return the most accurate AST we can. See issue for details.

    # If any expr is empty or whitespace only, we cannot convert to a literal.
    if any(part.expression.strip() == "" for part in template.interpolations):
        return _template_to_ast_constructor(template)

    try:
        # Wrap in parens to allow whitespace inside interpolation curly braces
        parsed = tuple(
            ast.parse(f"({part.expression})", mode="eval").body
            for part in template.interpolations
        )
    except SyntaxError:
        return _template_to_ast_constructor(template)

    return _template_to_ast_literal(template, parsed)


class _StringifierDict(dict):