Skip to content
Snippets Groups Projects
Commit 12860de8f2ed authored by Kodi Arfer's avatar Kodi Arfer
Browse files

bpo-43521: Allow ast.unparse with empty sets and NaN (GH-24897)


Automerge-Triggered-By: GH:pablogsal
parent 88b70bb52304
No related branches found
No related tags found
No related merge requests found
......@@ -1199,8 +1199,13 @@
def _write_constant(self, value):
if isinstance(value, (float, complex)):
# Substitute overflowing decimal literal for AST infinities.
self.write(repr(value).replace("inf", _INFSTR))
# Substitute overflowing decimal literal for AST infinities,
# and inf - inf for NaNs.
self.write(
repr(value)
.replace("inf", _INFSTR)
.replace("nan", f"({_INFSTR}-{_INFSTR})")
)
elif self._avoid_backslashes and isinstance(value, str):
self._write_str_avoiding_backslashes(value)
else:
......@@ -1273,7 +1278,6 @@
self.traverse(node.orelse)
def visit_Set(self, node):
if not node.elts:
raise ValueError("Set node should have at least one item")
if node.elts:
with self.delimit("{", "}"):
self.interleave(lambda: self.write(", "), self.traverse, node.elts)
......@@ -1278,5 +1282,9 @@
with self.delimit("{", "}"):
self.interleave(lambda: self.write(", "), self.traverse, node.elts)
else:
# `{}` would be interpreted as a dictionary literal, and
# `set` might be shadowed. Thus:
self.write('{*()}')
def visit_Dict(self, node):
def write_key_value_pair(k, v):
......
......@@ -199,6 +199,12 @@
self.check_ast_roundtrip("1e1000j")
self.check_ast_roundtrip("-1e1000j")
def test_nan(self):
self.assertASTEqual(
ast.parse(ast.unparse(ast.Constant(value=float('nan')))),
ast.parse('1e1000 - 1e1000')
)
def test_min_int(self):
self.check_ast_roundtrip(str(-(2 ** 31)))
self.check_ast_roundtrip(str(-(2 ** 63)))
......@@ -252,6 +258,12 @@
def test_set_literal(self):
self.check_ast_roundtrip("{'a', 'b', 'c'}")
def test_empty_set(self):
self.assertASTEqual(
ast.parse(ast.unparse(ast.Set(elts=[]))),
ast.parse('{*()}')
)
def test_set_comprehension(self):
self.check_ast_roundtrip("{x for x in range(5)}")
......@@ -326,9 +338,6 @@
def test_invalid_fstring_backslash(self):
self.check_invalid(ast.FormattedValue(value=ast.Constant(value="\\\\")))
def test_invalid_set(self):
self.check_invalid(ast.Set(elts=[]))
def test_invalid_yield_from(self):
self.check_invalid(ast.YieldFrom(value=None))
......
``ast.unparse`` can now render NaNs and empty sets.
0% Loading or .
You are about to add 0 people to the discussion. Proceed with caution.
Please register or to comment