🤖 get_repo_knowledge executed:

get_repo_knowledge RustPython/RustPython /tmp/coderabbit-repo-knowledge/rustpython-rustpython-3b4170e8/learnings

Length of output: 11534

🏁 Script executed:

sed -n '900,1020p' crates/vm/src/vm/vm_new.rs
sed -n '1135,1220p' crates/vm/src/vm/vm_new.rs
rg -n "invalid_except_stmt_end|except_as_end|end_offset" crates/vm/src/vm/vm_new.rs crates -g '*.rs'

Repository: RustPython/RustPython

Length of output: 16691

🏁 Script executed:

rg -n -C 5 "multiple exception types must be parenthesized when using 'as'|invalid_except_stmt|end_offset.*colon|colon.*end_offset" . -g '*.py' -g '*.rs' -g '*.md' -g '*.toml'
sed -n '260,320p' crates/vm/src/exceptions.rs

Repository: RustPython/RustPython

Length of output: 10241

🌐 Web query:

CPython test_syntax.py multiple exception types must be parenthesized when using as end_offset

💡 Result:

The CPython error "multiple exception types must be parenthesized" is a syntax error that occurs when legacy Python 2-style exception handling (e.g., except Exception, e:) is used in Python 3 [1][2][3]. In Python 3, multiple exception types must be grouped in a tuple using parentheses (e.g., except (Exception1, Exception2) as e:) [1][2]. Regarding your query about as and end_offset: 1. Error Message Evolution: The specific error message "multiple exception types must be parenthesized when using 'as'" was introduced in recent CPython versions to distinguish between plain missing parentheses and incorrect syntax when the as keyword is present [4]. 2. CPython Testing (test_syntax.py): In the CPython test suite (Lib/test/test_syntax.py), this error is tested by asserting that invalid except or except* statements raise a SyntaxError at specific locations [5][6]. The end_offset in these tests helps verify that the error points correctly to the range of the invalid syntax, particularly when complex try/except statements—or combinations of except and except*—are involved [6]. 3. Recent Changes: As of Python 3.14 (per PEP 758), it is now permissible to omit parentheses around groups of exceptions in except and except* clauses, provided that the as binding is not used [7][8]. If an as binding is present, parentheses remain mandatory, and the error message specifically reminds the user that they are required "when using 'as'" [4][8]. This error typically arises when running outdated code (often written for Python 2) on a modern Python 3 interpreter [1][3]. To resolve it, you must update the syntax to use as for exception aliasing and ensure multiple exception types are enclosed in a tuple [1][2].

Citations:

• 1: https://stackoverflow.com/questions/70648404/syntaxerror-multiple-exception-types-must-be-parenthesized
• 2: https://codegive.com/blog/python_syntaxerror_multiple_exception_types_must_be_parenthesized.php
• 3: https://stackoverflow.com/questions/74295016/syntaxerror-multiple-exception-types-must-be-parenthesized
• 4: encukou/cpython@c2ac662
• 5: https://github.com/python/cpython/blob/main/Lib/test/test_syntax.py
• 6: dicej/cpython@9c4232a
• 7: hugovk/cpython@c2ac662
• 8: GitHub issue 20768 in charliermarsh/ruff (link omitted to avoid creating a cross-reference)

🏁 Script executed:

python3 - <<'PY'
import sys
cases = [
    "try:\n    pass\nexcept A, B as exc:\n    pass\n",
    "try:\n    pass\nexcept A, B, C as exc:\n    pass\n",
    "try:\n    pass\nexcept A, B as exc:\\\n    pass\n",
]
print(sys.version)
for source in cases:
    try:
        compile(source, "<test>", "exec")
    except SyntaxError as error:
        print(repr(source))
        print({
            "lineno": error.lineno,
            "offset": error.offset,
            "end_lineno": error.end_lineno,
            "end_offset": error.end_offset,
            "text": error.text,
            "msg": error.msg,
        })
PY

Repository: RustPython/RustPython

Length of output: 663

🌐 Web query:

site:github.com/python/cpython Lib/test/test_syntax.py "multiple exception types must be parenthesized when using 'as'" "end_offset"

💡 Result:

The error message "multiple exception types must be parenthesized" is a syntax error in Python that occurs when listing multiple exception types in an except clause without enclosing them in parentheses [1]. Historically, Python required parentheses for multiple exceptions in an except statement (e.g., except (ExceptionA, ExceptionB):) [1]. Using a comma-separated list without parentheses was flagged with the SyntaxError: multiple exception types must be parenthesized [1]. More recently, starting in Python 3.14, the language began allowing unparenthesized multiple exception types in certain contexts as part of evolving syntax [2][3]. Because of this, modern static analysis tools like Ruff may flag unparenthesized exceptions as errors if they are configured for older versions of Python (e.g., Python 3.12) that do not yet support the newer, more permissive syntax [3]. The file Lib/test/test_syntax.py in the CPython source code is used to test that these and other syntax errors are correctly identified and raised by the interpreter [4][5]. The "end_offset" in your query likely refers to the column or character range (end_offset) tracked by the Python parser to highlight the specific area where the syntax error occurs, a feature improved in Python 3.10 and later to provide better error feedback [1].

Citations:

• 1: https://github.com/python/cpython/blob/main/Doc/whatsnew/3.10.rst?plain=1
• 2: https://github.com/python/cpython/blob/master/Grammar/python.gram
• 3: GitHub issue 144639 in python/cpython (link omitted to avoid creating a cross-reference)
• 4: https://github.com/python/cpython/blob/main/Lib/test/test_syntax.py
• 5: https://github.com/python/cpython/blob/main/Lib/test/test%5Fsyntax.py

🏁 Script executed:

python3 - <<'PY'
import sys
cases = [
    "try:\n    pass\nexcept A, B as exc:\n    pass\n",
    "try:\n    pass\nexcept A, B, C as exc:\n    pass\n",
]
print(sys.version)
for source in cases:
    try:
        compile(source, "<test>", "exec")
    except SyntaxError as error:
        print(repr(source))
        print({
            "lineno": error.lineno,
            "offset": error.offset,
            "end_lineno": getattr(error, "end_lineno", None),
            "end_offset": getattr(error, "end_offset", None),
            "text": error.text,
            "msg": error.msg,
        })
PY

Repository: RustPython/RustPython

Length of output: 594

🏁 Script executed:

curl -L --fail --silent --show-error \
  https://raw.githubusercontent.com/python/cpython/main/Lib/test/test_syntax.py |
  rg -n -C 12 "multiple exception types must be parenthesized when using"

Repository: RustPython/RustPython

Length of output: 1724

🏁 Script executed:

for file in Lib/test/test_syntax.py Lib/test/test_exceptions.py Lib/test/test_compile.py Grammar/python.gram; do
  echo "=== $file ==="
  curl -L --fail --silent --show-error "https://raw.githubusercontent.com/python/cpython/main/$file" |
    rg -n -C 5 "end_offset|invalid_except_stmt|multiple exception types must be parenthesized|RAISE_SYNTAX_ERROR_STARTING_FROM" || true
done

Repository: RustPython/RustPython

Length of output: 24692

🌐 Web query:

site:github.com/python/cpython "end_offset" "except A, B, C as"

💡 Result:

The term "end_offset" is not a keyword or standard syntax used in combination with "except A, B, C" in programming languages [1][2]. In the context of the Python programming language, "end_offset" is an attribute of the SyntaxError exception class (introduced in Python 3.10) [1][3] and a field used in the dis module for bytecode inspection [4]. It is not related to the "except" statement syntax [1][5]. If you are encountering a syntax error or a specific programming pattern involving "except A, B, C", please note the following regarding Python's exception handling: 1. Handling Multiple Exceptions: To catch multiple exception types, you use a tuple in the except clause [1]: try: # code that may raise exceptions pass except (A, B, C) as e: # handle exceptions A, B, or C pass 2. SyntaxError Context: The "end_offset" attribute is automatically populated by the Python parser when a SyntaxError is raised to indicate where the error ends in the source text [1][6]. It is not something you would typically use in an except clause [1]. If your query refers to a different language or a specific library's domain-specific language (DSL), please provide more context so the appropriate syntax can be identified.

Citations:

• 1: https://github.com/python/cpython/blob/main/Doc/library/exceptions.rst
• 2: https://github.com/python/cpython/blob/main/Lib/traceback.py
• 3: https://github.com/python/cpython/blob/main/Doc/whatsnew/3.10.rst?plain=1
• 4: https://github.com/python/cpython/blob/main/Doc/library/dis.rst?plain=1
• 5: https://github.com/python/cpython/blob/main/Lib/test/test_syntax.py
• 6: https://github.com/python/cpython/blob/3.10/Doc/library/exceptions.rst