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Merged
pablogsal merged 12 commits into from
Jun 27, 2026
+391 −182
Merged

gh-146495: Improve SyntaxError message for && and || operators #150906

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e309e5e
Improve SyntaxError message for and operators
Aniketsy Jun 4, 2026
02f650a
Add error location assertions for && and ||
Aniketsy Jun 4, 2026
3b0f068
📜🤖 Added by blurb_it.
blurb-it[bot] Jun 4, 2026
f527441
Fix && and || syntax error using invalid grammar rules
Aniketsy Jun 5, 2026
4d8f024
Update Misc/NEWS.d/next/Core_and_Builtins/2026-06-04-15-02-35.gh-issu…
Aniketsy Jun 11, 2026
5af9b3a
Add question marks for consistency in invalid_bitwise_and/or error me…
Aniketsy Jun 12, 2026
5aad775
Update Lib/test/test_syntax.py
Aniketsy Jun 12, 2026
9e22cfa
Update Lib/test/test_syntax.py
Aniketsy Jun 12, 2026
92e502a
add helper function in parser
Aniketsy Jun 14, 2026
476243d
add tests with space
Aniketsy Jun 14, 2026
7f86edd
improve tests
Aniketsy Jun 14, 2026
1415a98
improve tests
Aniketsy Jun 14, 2026
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16 changes: 16 additions & 0 deletions Grammar/python.gram
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Original file line number Diff line number Diff line change
Expand Up @@ -819,6 +819,7 @@ is_bitwise_or[CmpopExprPair*]: 'is' a=bitwise_or { _PyPegen_cmpop_expr_pair(p, I

bitwise_or[expr_ty]:
| a=bitwise_or '|' b=bitwise_xor { _PyAST_BinOp(a, BitOr, b, EXTRA) }
| invalid_bitwise_or
| bitwise_xor

bitwise_xor[expr_ty]:
Expand All @@ -827,6 +828,7 @@ bitwise_xor[expr_ty]:

bitwise_and[expr_ty]:
| a=bitwise_and '&' b=shift_expr { _PyAST_BinOp(a, BitAnd, b, EXTRA) }
| invalid_bitwise_and
| shift_expr

shift_expr[expr_ty]:
Expand Down Expand Up @@ -1638,3 +1640,17 @@ invalid_type_params:
RAISE_SYNTAX_ERROR_STARTING_FROM(
token,
"Type parameter list cannot be empty")}

invalid_bitwise_and:
| a=bitwise_and b='&' c='&' {
_PyPegen_tokens_are_adjacent(b, c)
? RAISE_SYNTAX_ERROR_KNOWN_RANGE(b, c, "invalid syntax. Maybe you meant 'and' or '&' instead of '&&'?")
: NULL
}

invalid_bitwise_or:
| a=bitwise_or b='|' c='|' {
_PyPegen_tokens_are_adjacent(b, c)
? RAISE_SYNTAX_ERROR_KNOWN_RANGE(b, c, "invalid syntax. Maybe you meant 'or' or '|' instead of '||'?")
: NULL
}
44 changes: 44 additions & 0 deletions Lib/test/test_syntax.py
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Original file line number Diff line number Diff line change
Expand Up @@ -3505,6 +3505,50 @@ def test_ifexp_body_stmt_else_stmt(self):
]:
self._check_error(f"x = {lhs_stmt} if 1 else {rhs_stmt}", msg)

def test_double_ampersand(self):
self._check_error(
"a && b",
r"Maybe you meant 'and' or '&' instead of '&&'\?",
lineno=1,
end_lineno=1,
offset=3,
end_offset=5,
)
self._check_error(
"a & & b",
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"invalid syntax",
Comment thread
serhiy-storchaka marked this conversation as resolved.
lineno=1,
end_lineno=1,
offset=5,
end_offset=6,
)
self._check_error(
"(a &\n & b)",
"invalid syntax",
lineno=2,
end_lineno=2,
offset=5,
end_offset=6,
)

def test_double_pipe(self):
self._check_error(
"a || b",
r"Maybe you meant 'or' or '|' instead of '||'\?",
lineno=1,
end_lineno=1,
offset=3,
end_offset=5,
)
self._check_error(
"a | | b",
"invalid syntax",
lineno=1,
end_lineno=1,
offset=5,
end_offset=6,
)


class LazyImportRestrictionTestCase(SyntaxErrorTestCase):
"""Test syntax restrictions for lazy imports."""
Expand Down
1 change: 1 addition & 0 deletions Misc/NEWS.d/next/Core_and_Builtins/2026-06-04-15-02-35.gh-issue-146495.wWRRvx.rst
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Original file line number Diff line number Diff line change
@@ -0,0 +1 @@
Improve :exc:`SyntaxError` message for ``&&`` and ``||`` operators, suggesting ``and``/``&`` and ``or``/``|`` respectively.
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