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
188
189
190
191
192
|
"""Class based built-in exception hierarchy.
New with Python 1.5, all standard built-in exceptions are now class objects by
default. This gives Python's exception handling mechanism a more
object-oriented feel. Traditionally they were string objects. Python will
fallback to string based exceptions if the interpreter is invoked with the -X
option, or if some failure occurs during class exception initialization (in
this case a warning will be printed).
Most existing code should continue to work with class based exceptions. Some
tricky uses of IOError may break, but the most common uses should work.
Here is a rundown of the class hierarchy. You can change this by editing this
file, but it isn't recommended. The class names described here are expected
to be found by the bltinmodule.c file.
The classes with a `*' are new as of Python 1.5. They are defined as tuples
containing the derived exceptions when string-based exceptions are used. If
you define your own class based exceptions, they should be derived from
Exception.
Exception(*)
|
+-- StandardError(*)
|
+-- SystemExit
+-- KeyboardInterrupt
+-- ImportError
+-- EnvironmentError(*)
| |
| +-- IOError
| +-- OSError(*)
|
+-- EOFError
+-- RuntimeError
+-- NameError
+-- AttributeError
+-- SyntaxError
+-- TypeError
+-- AssertionError
+-- LookupError(*)
| |
| +-- IndexError
| +-- KeyError
|
+-- ArithmeticError(*)
| |
| +-- OverflowError
| +-- ZeroDivisionError
| +-- FloatingPointError
|
+-- ValueError
+-- SystemError
+-- MemoryError
"""
class Exception:
def __init__(self, *args):
self.args = args
def __str__(self):
if not self.args:
return ''
elif len(self.args) == 1:
return str(self.args[0])
else:
return str(self.args)
def __getitem__(self, i):
return self.args[i]
class StandardError(Exception):
pass
class SyntaxError(StandardError):
filename = lineno = offset = text = None
msg = ""
def __init__(self, *args):
self.args = args
if len(self.args) >= 1:
self.msg = self.args[0]
if len(self.args) == 2:
info = self.args[1]
try:
self.filename, self.lineno, self.offset, self.text = info
except:
pass
def __str__(self):
return str(self.msg)
class EnvironmentError(StandardError):
"""Base class for exceptions that occur outside the Python system.
Primarily used as a base class for OSError and IOError."""
def __init__(self, *args):
self.args = args
self.errno = None
self.strerror = None
self.filename = None
if len(args) == 3:
# open() errors give third argument which is the filename. BUT,
# so common in-place unpacking doesn't break, e.g.:
#
# except IOError, (errno, strerror):
#
# we hack args so that it only contains two items. This also
# means we need our own __str__() which prints out the filename
# when it was supplied.
self.errno, self.strerror, self.filename = args
self.args = args[0:2]
if len(args) == 2:
# common case: PyErr_SetFromErrno()
self.errno, self.strerror = args
def __str__(self):
if self.filename is not None:
return '[Errno %s] %s: %s' % (self.errno, self.strerror,
repr(self.filename))
elif self.errno and self.strerror:
return '[Errno %s] %s' % (self.errno, self.strerror)
else:
return StandardError.__str__(self)
class IOError(EnvironmentError):
pass
class OSError(EnvironmentError):
"""Used by the posix module."""
pass
class RuntimeError(StandardError):
pass
class SystemError(StandardError):
pass
class EOFError(StandardError):
pass
class ImportError(StandardError):
pass
class TypeError(StandardError):
pass
class ValueError(StandardError):
pass
class KeyboardInterrupt(StandardError):
pass
class AssertionError(StandardError):
pass
class ArithmeticError(StandardError):
pass
class OverflowError(ArithmeticError):
pass
class FloatingPointError(ArithmeticError):
pass
class ZeroDivisionError(ArithmeticError):
pass
class LookupError(StandardError):
pass
class IndexError(LookupError):
pass
class KeyError(LookupError):
pass
class AttributeError(StandardError):
pass
class NameError(StandardError):
pass
class MemoryError(StandardError):
pass
class SystemExit(Exception):
def __init__(self, *args):
self.args = args
if len(args) == 0:
self.code = None
elif len(args) == 1:
self.code = args[0]
else:
self.code = args
|
