`ast.parse()` inconsistency with type comments vs. `type: ignore`

[tusharsadhwani]

Bug report

Bug description:

Consider the following two code snippets:

with (x, y):
  pass

and:

with x, y:
  pass

They produce an identical AST, unless we try to parse type comments, in which case they deviate.

---

In case of a type COMMENT, we get DIFFERENT ASTs, with and without the brackets:

>>> import ast
>>> x = '''
... with (x, y): # type: int
...   pass
... '''
>>> y = '''
... with x, y: # type: int
...   pass
... '''
>>> print(ast.dump(ast.parse(x, type_comments=True), indent=2))
Module(
  body=[
    With(
      items=[
        withitem(
          context_expr=Tuple(
            elts=[
              Name(id='x', ctx=Load()),
              Name(id='y', ctx=Load())],
            ctx=Load()))],
      body=[
        Pass()],
      type_comment='int')],
  type_ignores=[])
>>> print(ast.dump(ast.parse(y, type_comments=True), indent=2))
Module(
  body=[
    With(
      items=[
        withitem(
          context_expr=Name(id='x', ctx=Load())),
        withitem(
          context_expr=Name(id='y', ctx=Load()))],
      body=[
        Pass()],
      type_comment='int')],
  type_ignores=[])

In case of type IGNORE, we get IDENTICAL ASTs with or without bracket:

>>> x = '''
... with (x, y): # type: ignore
...   pass
... '''
>>> y = '''
... with x, y: # type: ignore
...   pass
... '''
>>> print(ast.dump(ast.parse(x, type_comments=True), indent=2))
Module(
  body=[
    With(
      items=[
        withitem(
          context_expr=Name(id='x', ctx=Load())),
        withitem(
          context_expr=Name(id='y', ctx=Load()))],
      body=[
        Pass()])],
  type_ignores=[
    TypeIgnore(lineno=2, tag='')])
>>> print(ast.dump(ast.parse(y, type_comments=True), indent=2))
Module(
  body=[
    With(
      items=[
        withitem(
          context_expr=Name(id='x', ctx=Load())),
        withitem(
          context_expr=Name(id='y', ctx=Load()))],
      body=[
        Pass()])],
  type_ignores=[
    TypeIgnore(lineno=2, tag='')])

CPython versions tested on:

CPython main branch

Operating systems tested on:

macOS

[sobolevn]

Sorry, I can't reproduce this problem on main with 3.14:

~/Desktop/cpython  main ✔                                                                 
» echo "                        
with (x, y):  # type: int
  pass
" | ./python.exe -m ast     
Module(
   body=[
      With(
         items=[
            withitem(
               context_expr=Name(id='x', ctx=Load())),
            withitem(
               context_expr=Name(id='y', ctx=Load()))],
         body=[
            Pass()],
         type_comment='int')])

~/Desktop/cpython  main ✔                                                                 
» echo " 
with x, y:  # type: int 
  pass
" | ./python.exe -m ast
Module(
   body=[
      With(
         items=[
            withitem(
               context_expr=Name(id='x', ctx=Load())),
            withitem(
               context_expr=Name(id='y', ctx=Load()))],
         body=[
            Pass()],
         type_comment='int')])

What python version are you using?

Looks like it can be reproduced on 3.11 and 3.12:

~/Desktop/cpython  main ✔                                                                 
» pyenv local 3.12
                                                                                           
~/Desktop/cpython  main ✗                                                                 
» echo "          
with (x, y):  # type: int
  pass
" | python -m ast
Module(
   body=[
      With(
         items=[
            withitem(
               context_expr=Tuple(
                  elts=[
                     Name(id='x', ctx=Load()),
                     Name(id='y', ctx=Load())],
                  ctx=Load()))],
         body=[
            Pass()],
         type_comment='int')],
   type_ignores=[])

[tusharsadhwani]

My mistake. I was on 3.12 by accident.