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ast.Return

functions and classes

Node for the return statement: value is the returned expression, or None for a bare return.

Syntax

ast.Return(value=None)

A bare return and return None differ in the tree: in the first value is None, in the second it is Constant(None). return a, b puts a single Tuple into value. ast.parse accepts return outside a function, and only compile() reports "'return' outside function", because parsing and context checks are separate.

Examples

import ast
print(ast.parse('return').body[0].value)  # → None
print(type(ast.parse('return None').body[0].value).__name__)  # → Constant
print(type(ast.parse('return a, b').body[0].value).__name__)  # → Tuple

import ast
try:
    compile(ast.parse('return 1'), '<ast>', 'exec')
except SyntaxError as e:
    print(e.msg)  # → 'return' outside function

See also

Common errors

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