all Python 3until 3.14Removed from the standard libraryterm

ast.Num / ast.Str / ast.Bytes / ast.NameConstant / ast.Ellipsis

removed

Legacy ast node classes for numbers, strings, bytes, None/True/False and the ellipsis. Removed in Python 3.14 — use ast.Constant.

Syntax

isinstance(node, ast.Num)  # до 3.14

Before Python 3.8 the parser produced a separate node for each kind of literal: Num with an n field, Str and Bytes with an s field, NameConstant and Ellipsis. Since 3.8 it emits a single ast.Constant node, and the old names survived as compatibility shims, now removed together with the n and s fields. To migrate, replace isinstance(node, ast.Num) with isinstance(node, ast.Constant) plus a check on the value type, e.g. isinstance(node.value, int); node.n and node.s become node.value; the visit_Num and visit_Str methods of a NodeVisitor become one visit_Constant; ast.Num(n=1) in tree building becomes ast.Constant(value=1).

Examples

# Python 3.14+
import ast
try:
    ast.Num
except AttributeError as e:
    print(type(e).__name__)  # → AttributeError

# Python 3.14+
import ast
class Literals(ast.NodeVisitor):
    def visit_Constant(self, node):
        print(type(node.value).__name__, repr(node.value))
Literals().visit(ast.parse("x = 42 + len('hi')"))
# → int 42
# → str 'hi'

import ast
node = ast.parse('42').body[0].value
print(isinstance(node, ast.Num), node.n)  # → True 42
print(type(node).__name__)  # → Constant

Common errors

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