Python code coverage for Lib/lib2to3/fixes/fix_except.py

#	count	content
1	n/a	"""Fixer for except statements with named exceptions.
2	n/a
3	n/a	The following cases will be converted:
4	n/a
5	n/a	- "except E, T:" where T is a name:
6	n/a
7	n/a	except E as T:
8	n/a
9	n/a	- "except E, T:" where T is not a name, tuple or list:
10	n/a
11	n/a	except E as t:
12	n/a	T = t
13	n/a
14	n/a	This is done because the target of an "except" clause must be a
15	n/a	name.
16	n/a
17	n/a	- "except E, T:" where T is a tuple or list literal:
18	n/a
19	n/a	except E as t:
20	n/a	T = t.args
21	n/a	"""
22	n/a	# Author: Collin Winter
23	n/a
24	n/a	# Local imports
25	n/a	from .. import pytree
26	n/a	from ..pgen2 import token
27	n/a	from .. import fixer_base
28	n/a	from ..fixer_util import Assign, Attr, Name, is_tuple, is_list, syms
29	n/a
30	n/a	def find_excepts(nodes):
31	n/a	for i, n in enumerate(nodes):
32	n/a	if n.type == syms.except_clause:
33	n/a	if n.children[0].value == 'except':
34	n/a	yield (n, nodes[i+2])
35	n/a
36	n/a	class FixExcept(fixer_base.BaseFix):
37	n/a	BM_compatible = True
38	n/a
39	n/a	PATTERN = """
40	n/a	try_stmt< 'try' ':' (simple_stmt \| suite)
41	n/a	cleanup=(except_clause ':' (simple_stmt \| suite))+
42	n/a	tail=(['except' ':' (simple_stmt \| suite)]
43	n/a	['else' ':' (simple_stmt \| suite)]
44	n/a	['finally' ':' (simple_stmt \| suite)]) >
45	n/a	"""
46	n/a
47	n/a	def transform(self, node, results):
48	n/a	syms = self.syms
49	n/a
50	n/a	tail = [n.clone() for n in results["tail"]]
51	n/a
52	n/a	try_cleanup = [ch.clone() for ch in results["cleanup"]]
53	n/a	for except_clause, e_suite in find_excepts(try_cleanup):
54	n/a	if len(except_clause.children) == 4:
55	n/a	(E, comma, N) = except_clause.children[1:4]
56	n/a	comma.replace(Name("as", prefix=" "))
57	n/a
58	n/a	if N.type != token.NAME:
59	n/a	# Generate a new N for the except clause
60	n/a	new_N = Name(self.new_name(), prefix=" ")
61	n/a	target = N.clone()
62	n/a	target.prefix = ""
63	n/a	N.replace(new_N)
64	n/a	new_N = new_N.clone()
65	n/a
66	n/a	# Insert "old_N = new_N" as the first statement in
67	n/a	# the except body. This loop skips leading whitespace
68	n/a	# and indents
69	n/a	#TODO(cwinter) suite-cleanup
70	n/a	suite_stmts = e_suite.children
71	n/a	for i, stmt in enumerate(suite_stmts):
72	n/a	if isinstance(stmt, pytree.Node):
73	n/a	break
74	n/a
75	n/a	# The assignment is different if old_N is a tuple or list
76	n/a	# In that case, the assignment is old_N = new_N.args
77	n/a	if is_tuple(N) or is_list(N):
78	n/a	assign = Assign(target, Attr(new_N, Name('args')))
79	n/a	else:
80	n/a	assign = Assign(target, new_N)
81	n/a
82	n/a	#TODO(cwinter) stopgap until children becomes a smart list
83	n/a	for child in reversed(suite_stmts[:i]):
84	n/a	e_suite.insert_child(0, child)
85	n/a	e_suite.insert_child(i, assign)
86	n/a	elif N.prefix == "":
87	n/a	# No space after a comma is legal; no space after "as",
88	n/a	# not so much.
89	n/a	N.prefix = " "
90	n/a
91	n/a	#TODO(cwinter) fix this when children becomes a smart list
92	n/a	children = [c.clone() for c in node.children[:3]] + try_cleanup + tail
93	n/a	return pytree.Node(node.type, children)