blob: 418fee2988fc01f513840190d602723197e62321 (
plain)
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
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
|
"""Tests for used-before-assignment with assignments in except handlers after
try blocks with return statements.
See: https://github.com/pylint-dev/pylint/issues/5500.
"""
# pylint: disable=inconsistent-return-statements,broad-exception-raised
def function():
"""Assume except blocks execute if the try block returns."""
try:
success_message = "success message"
return success_message
except ValueError:
failure_message = "failure message"
finally:
print(failure_message) # [used-before-assignment]
return failure_message
def func_ok(var):
"""'msg' is defined in all ExceptHandlers."""
try:
return 1 / var.some_other_func()
except AttributeError:
msg = "Attribute not defined"
except ZeroDivisionError:
msg = "Division by 0"
print(msg)
def func_ok2(var):
"""'msg' is defined in all ExceptHandlers that don't raise an Exception."""
try:
return 1 / var.some_other_func()
except AttributeError as ex:
raise Exception from ex
except ZeroDivisionError:
msg = "Division by 0"
print(msg)
def func_ok3(var):
"""'msg' is defined in all ExceptHandlers that don't return."""
try:
return 1 / var.some_other_func()
except AttributeError:
return
except ZeroDivisionError:
msg = "Division by 0"
print(msg)
def func_ok4(var):
"""Define "msg" with a chained assignment."""
try:
return 1 / var.some_other_func()
except AttributeError:
msg2 = msg = "Division by 0"
print(msg2)
except ZeroDivisionError:
msg = "Division by 0"
print(msg)
def func_ok5(var):
"""Define 'msg' via unpacked iterable."""
try:
return 1 / var.some_other_func()
except AttributeError:
msg, msg2 = ["Division by 0", "Division by 0"]
print(msg2)
except ZeroDivisionError:
msg = "Division by 0"
print(msg)
def func_ok6(var):
"""Define 'msg' in one handler nested under if block."""
err_message = "Division by 0"
try:
return 1 / var.some_other_func()
except ZeroDivisionError:
if err_message:
msg = "Division by 0"
else:
msg = None
print(msg)
def func_ok7(var):
"""Define 'msg' in one handler nested under with statement."""
try:
return 1 / var.some_other_func()
except ZeroDivisionError:
with open(__file__, encoding='utf-8') as my_file:
msg = "Division by 0"
my_file.write(msg)
print(msg)
def func_ok8(var):
"""Define 'msg' in one handler via type annotation."""
try:
return 1 / var.some_other_func()
except ZeroDivisionError:
# See func_invalid2() for mere annotation without value
msg: str = "Division by 0"
print(msg)
def func_invalid1(var):
"""'msg' is not defined in one handler."""
try:
return 1 / var.some_other_func()
except AttributeError:
pass
except ZeroDivisionError:
msg = "Division by 0"
print(msg) # [used-before-assignment]
def func_invalid2(var):
"""'msg' is not defined in one handler."""
try:
return 1 / var.some_other_func()
except AttributeError:
msg: str
except ZeroDivisionError:
msg = "Division by 0"
print(msg) # [used-before-assignment]
def func_invalid3(var):
"""'msg' is not defined in one handler, but is defined in another
nested under an if. Nesting under an if tests that the implementation
does not assume direct parentage between `msg=` and `except`, and
the prior except is necessary to raise the message.
"""
err_message = False
try:
return 1 / var.some_other_func()
except AttributeError:
pass
except ZeroDivisionError:
if err_message:
msg = "Division by 0"
else:
msg = None
print(msg) # [used-before-assignment]
def func_invalid4(var):
"""Define 'msg' in one handler nested under with statement."""
try:
return 1 / var.some_other_func()
except AttributeError:
pass
except ZeroDivisionError:
with open(__file__, encoding='utf-8') as my_file:
msg = "Division by 0"
my_file.write("****")
print(msg) # [used-before-assignment]
def func_invalid5(var):
"""Define 'msg' in one handler only via chained assignment."""
try:
return 1 / var.some_other_func()
except AttributeError:
pass
except ZeroDivisionError:
msg2 = msg = "Division by 0"
print(msg2)
print(msg) # [used-before-assignment]
def func_invalid6(var):
"""Define 'msg' in one handler only via unpacked iterable."""
try:
return 1 / var.some_other_func()
except AttributeError:
pass
except ZeroDivisionError:
msg, msg2 = ["Division by 0"] * 2
print(msg2)
print(msg) # [used-before-assignment]
|
