1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
|
"""
Checks that value used in a subscript supports subscription
(i.e. defines __getitem__ method).
"""
# pylint: disable=missing-docstring,pointless-statement,expression-not-assigned,wrong-import-position, unnecessary-comprehension
# pylint: disable=too-few-public-methods,import-error,invalid-name,wrong-import-order, useless-object-inheritance, redundant-u-string-prefix
import six
# primitives
numbers = [1, 2, 3]
numbers[0]
"123"[0]
u"123"[0]
b"123"[0]
bytearray(b"123")[0]
dict(a=1, b=2)['a']
(1, 2, 3)[0]
# list/dict comprehensions are fine
[x for x in range(10)][0]
{x: 10 - x for x in range(10)}[0]
# instances
class NonSubscriptable(object):
pass
class Subscriptable(object):
def __getitem__(self, key):
return key + key
NonSubscriptable()[0] # [unsubscriptable-object]
NonSubscriptable[0] # [unsubscriptable-object]
Subscriptable()[0]
Subscriptable[0] # [unsubscriptable-object]
# generators are not subscriptable
def powers_of_two():
k = 0
while k < 10:
yield 2 ** k
k += 1
powers_of_two()[0] # [unsubscriptable-object]
powers_of_two[0] # [unsubscriptable-object]
# check that primitive non subscriptable types are caught
True[0] # [unsubscriptable-object]
None[0] # [unsubscriptable-object]
8.5[0] # [unsubscriptable-object]
10[0] # [unsubscriptable-object]
# sets are not subscriptable
{x ** 2 for x in range(10)}[0] # [unsubscriptable-object]
set(numbers)[0] # [unsubscriptable-object]
frozenset(numbers)[0] # [unsubscriptable-object]
# skip instances with unknown base classes
from some_missing_module import LibSubscriptable
class MaybeSubscriptable(LibSubscriptable):
pass
MaybeSubscriptable()[0]
# subscriptable classes (through metaclasses)
class MetaSubscriptable(type):
def __getitem__(cls, key):
return key + key
class SubscriptableClass(six.with_metaclass(MetaSubscriptable, object)):
pass
SubscriptableClass[0]
SubscriptableClass()[0] # [unsubscriptable-object]
# functions are not subscriptable
def test(*args, **kwargs):
return args, kwargs
test()[0]
test[0] # [unsubscriptable-object]
# deque
from collections import deque
deq = deque(maxlen=10)
deq.append(42)
deq[0]
class AbstractClass(object):
def __init__(self):
self.ala = {i for i in range(10)}
self.bala = [i for i in range(10)]
self.portocala = None
def test_unsubscriptable(self):
self.bala[0]
self.portocala[0]
class ClassMixin(object):
def __init__(self):
self.ala = {i for i in range(10)}
self.bala = [i for i in range(10)]
self.portocala = None
def test_unsubscriptable(self):
self.bala[0]
self.portocala[0]
def return_an_int(param):
"""Returns an int"""
if param == 0:
return 1
return 0
def test_one(param):
"""Should complain about var_one[0], but doesn't"""
var_one = return_an_int(param)
return var_one[0] # [unsubscriptable-object]
|
