Mercurial > repos > shellac > guppy_basecaller

comparison env/lib/python3.7/site-packages/libfuturize/fixes/fix_raise.py @ 2:6af9afd405e9 draft

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
"planemo upload commit 0a63dd5f4d38a1f6944587f52a8cd79874177fc1"
author shellac
date Thu, 14 May 2020 14:56:58 -0400
parents 26e78fe6e8c4
children
comparison
equal deleted inserted replaced
1:75ca89e9b81c 2:6af9afd405e9
1 """Fixer for 'raise E, V'
2
3 From Armin Ronacher's ``python-modernize``.
4
5 raise -> raise
6 raise E -> raise E
7 raise E, 5 -> raise E(5)
8 raise E, 5, T -> raise E(5).with_traceback(T)
9 raise E, None, T -> raise E.with_traceback(T)
10
11 raise (((E, E'), E''), E'''), 5 -> raise E(5)
12 raise "foo", V, T -> warns about string exceptions
13
14 raise E, (V1, V2) -> raise E(V1, V2)
15 raise E, (V1, V2), T -> raise E(V1, V2).with_traceback(T)
16
17
18 CAVEATS:
19 1) "raise E, V, T" cannot be translated safely in general. If V
20 is not a tuple or a (number, string, None) literal, then:
21
22 raise E, V, T -> from future.utils import raise_
23 raise_(E, V, T)
24 """
25 # Author: Collin Winter, Armin Ronacher, Mark Huang
26
27 # Local imports
28 from lib2to3 import pytree, fixer_base
29 from lib2to3.pgen2 import token
30 from lib2to3.fixer_util import Name, Call, is_tuple, Comma, Attr, ArgList
31
32 from libfuturize.fixer_util import touch_import_top
33
34
35 class FixRaise(fixer_base.BaseFix):
36
37 BM_compatible = True
38 PATTERN = """
39 raise_stmt< 'raise' exc=any [',' val=any [',' tb=any]] >
40 """
41
42 def transform(self, node, results):
43 syms = self.syms
44
45 exc = results["exc"].clone()
46 if exc.type == token.STRING:
47 msg = "Python 3 does not support string exceptions"
48 self.cannot_convert(node, msg)
49 return
50
51 # Python 2 supports
52 # raise ((((E1, E2), E3), E4), E5), V
53 # as a synonym for
54 # raise E1, V
55 # Since Python 3 will not support this, we recurse down any tuple
56 # literals, always taking the first element.
57 if is_tuple(exc):
58 while is_tuple(exc):
59 # exc.children[1:-1] is the unparenthesized tuple
60 # exc.children[1].children[0] is the first element of the tuple
61 exc = exc.children[1].children[0].clone()
62 exc.prefix = u" "
63
64 if "tb" in results:
65 tb = results["tb"].clone()
66 else:
67 tb = None
68
69 if "val" in results:
70 val = results["val"].clone()
71 if is_tuple(val):
72 # Assume that exc is a subclass of Exception and call exc(*val).
73 args = [c.clone() for c in val.children[1:-1]]
74 exc = Call(exc, args)
75 elif val.type in (token.NUMBER, token.STRING):
76 # Handle numeric and string literals specially, e.g.
77 # "raise Exception, 5" -> "raise Exception(5)".
78 val.prefix = u""
79 exc = Call(exc, [val])
80 elif val.type == token.NAME and val.value == u"None":
81 # Handle None specially, e.g.
82 # "raise Exception, None" -> "raise Exception".
83 pass
84 else:
85 # val is some other expression. If val evaluates to an instance
86 # of exc, it should just be raised. If val evaluates to None,
87 # a default instance of exc should be raised (as above). If val
88 # evaluates to a tuple, exc(*val) should be called (as
89 # above). Otherwise, exc(val) should be called. We can only
90 # tell what to do at runtime, so defer to future.utils.raise_(),
91 # which handles all of these cases.
92 touch_import_top(u"future.utils", u"raise_", node)
93 exc.prefix = u""
94 args = [exc, Comma(), val]
95 if tb is not None:
96 args += [Comma(), tb]
97 return Call(Name(u"raise_"), args)
98
99 if tb is not None:
100 tb.prefix = ""
101 exc_list = Attr(exc, Name('with_traceback')) + [ArgList([tb])]
102 else:
103 exc_list = [exc]
104
105 return pytree.Node(syms.raise_stmt,
106 [Name(u"raise")] + exc_list,
107 prefix=node.prefix)