bpo-38870: Do not separate factor prefixes in ast.unparse (GH-20133)
diff --git a/Lib/ast.py b/Lib/ast.py
index 7a43581..1de37b9 100644
--- a/Lib/ast.py
+++ b/Lib/ast.py
@@ -1190,10 +1190,10 @@
unop = {"Invert": "~", "Not": "not", "UAdd": "+", "USub": "-"}
unop_precedence = {
- "~": _Precedence.FACTOR,
"not": _Precedence.NOT,
+ "~": _Precedence.FACTOR,
"+": _Precedence.FACTOR,
- "-": _Precedence.FACTOR
+ "-": _Precedence.FACTOR,
}
def visit_UnaryOp(self, node):
@@ -1201,7 +1201,10 @@
operator_precedence = self.unop_precedence[operator]
with self.require_parens(operator_precedence, node):
self.write(operator)
- self.write(" ")
+ # factor prefixes (+, -, ~) shouldn't be seperated
+ # from the value they belong, (e.g: +1 instead of + 1)
+ if operator_precedence is not _Precedence.FACTOR:
+ self.write(" ")
self.set_precedence(operator_precedence, node.operand)
self.traverse(node.operand)
diff --git a/Lib/test/test_unparse.py b/Lib/test/test_unparse.py
index 2be44b2..1393bcc 100644
--- a/Lib/test/test_unparse.py
+++ b/Lib/test/test_unparse.py
@@ -347,7 +347,7 @@
self.check_src_roundtrip("(1 + 2) / 3")
self.check_src_roundtrip("(1 + 2) * 3 + 4 * (5 + 2)")
self.check_src_roundtrip("(1 + 2) * 3 + 4 * (5 + 2) ** 2")
- self.check_src_roundtrip("~ x")
+ self.check_src_roundtrip("~x")
self.check_src_roundtrip("x and y")
self.check_src_roundtrip("x and y and z")
self.check_src_roundtrip("x and (y and x)")
@@ -401,6 +401,12 @@
self.check_ast_roundtrip(src)
self.check_src_dont_roundtrip(src)
+ def test_unary_op_factor(self):
+ for prefix in ("+", "-", "~"):
+ self.check_src_roundtrip(f"{prefix}1")
+ for prefix in ("not",):
+ self.check_src_roundtrip(f"{prefix} 1")
+
class DirectoryTestCase(ASTTestCase):
"""Test roundtrip behaviour on all files in Lib and Lib/test."""