Confusing SyntaxError for multi-line string concatenation with missing comma

[lucaswerkmeister]

Bug report

Bug description:

I just spent a couple of minutes figuring out what was wrong with this code:

import sys

print(
    "\n"
    "Notice: a Git repository with 'main' and 'doc' branches has been set up.\n"
    "You will probably want to amend the initial commit on the 'main' branch.\n"
    file=sys.stderr
)

It produces the following error:

  File "/tmp/tmp.py", line 4
    "\n"
    ^^^^
SyntaxError: invalid syntax. Perhaps you forgot a comma?

Which had me looking at the "\n" line and trying to confirm if Python even has string literal concatenation like I seemed to remember (it does). The error was actually two lines further down, at the end of the concatenated string literal: that line was missing the comma (fix).

Would it be possible to improve the error message, moving it to the last line of the string literal that doesn’t have a comma?

CPython versions tested on:

3.14, 3.13, 3.15

Operating systems tested on:

Linux

Linked PRs

• gh-142236: Fix incorrect keyword suggestions for syntax errors #142328
• gh-142236: Improve error location for missing comma in string concatenations #142330

[lucaswerkmeister]

(Not sure if “bug” is the right type for this, feel free to re-label – or close, for that matter. But I thought you might want to hear about a confusing error message :))

[johnslavik]

CC @ZeroIntensity (mentorship): That would be topic-parser I think.

I may give this a shot later this week.

[StanFromIreland]

The suggestion I get on main in the repl is even worse:

  File "<python-input-0>", line 4
    print(
    ^^^^^
SyntaxError: invalid syntax. Did you mean 'not'?

[StanFromIreland]

It's traceback.py. CC @pablogsal

[johnslavik]

@StanFromIreland If it's traceback.py, then maybe let's also add stdlib.

[StanFromIreland]

Let's deal with the first issue for now.

[lucaswerkmeister]

The suggestion I get on main in the repl is even worse:

  File "<python-input-0>", line 4
    print(
    ^^^^^
SyntaxError: invalid syntax. Did you mean 'not'?

FWIW, I got a similar error earlier when I tried out the input in a REPL, but the previous error when evaluating a .py file.

shell session

$ docker run --rm -it --entrypoint=bash python:3.15-rc-trixie
root@6282dd65901a:/# python
Python 3.15.0a2 (main, Nov 19 2025, 18:40:55) [GCC 14.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys
... 
... print(
...     "\n"
...     "Notice: a Git repository with 'main' and 'doc' branches has been set up.\n"
...     "You will probably want to amend the initial commit on the 'main' branch.\n"
...     file=sys.stderr
... )
... 
  File "<python-input-0>", line 4
    print(
    ^^^^^
SyntaxError: invalid syntax. Did you mean 'not'?
>>> 
root@6282dd65901a:/# cat >| /tmp/tmp.py
import sys

print(
    "\n"
    "Notice: a Git repository with 'main' and 'doc' branches has been set up.\n"
    "You will probably want to amend the initial commit on the 'main' branch.\n"
    file=sys.stderr
)
root@6282dd65901a:/# python /tmp/tmp.py
  File "/tmp/tmp.py", line 4
    "\n"
    ^^^^
SyntaxError: invalid syntax. Perhaps you forgot a comma?