错误信息打印：
1 ''' 2 Created on 2018年7月28日 3 @filename: error_info.py 4 @author: liupf 5 ''' 6 ''' 7 try: 8 print('try...') 9 r = 10 / 1#int('a') 10 print('result:', r) 11 except ZeroDivisionError as e: 12 print('except:', e) 13 except ValueError as e: 14 print('ValueError:', e) 15 else: 16 print("no error") 17 finally: 18 print('finally...') 19 print('END') 20 ''' 21 #异常类的继承关系 22 #https://docs.python.org/3/library/exceptions.html#exception-hierarchy 23 ''' 24 BaseException 25 +-- SystemExit 26 +-- KeyboardInterrupt 27 +-- GeneratorExit 28 +-- Exception 29 +-- StopIteration 30 +-- StopAsyncIteration 31 +-- ArithmeticError 32 | +-- FloatingPointError 33 | +-- OverflowError 34 | +-- ZeroDivisionError 35 +-- AssertionError 36 +-- AttributeError 37 +-- BufferError 38 +-- EOFError 39 +-- ImportError 40 | +-- ModuleNotFoundError 41 +-- LookupError 42 | +-- IndexError 43 | +-- KeyError 44 +-- MemoryError 45 +-- NameError 46 | +-- UnboundLocalError 47 +-- OSError 48 | +-- BlockingIOError 49 | +-- ChildProcessError 50 | +-- ConnectionError 51 | | +-- BrokenPipeError 52 | | +-- ConnectionAbortedError 53 | | +-- ConnectionRefusedError 54 | | +-- ConnectionResetError 55 | +-- FileExistsError 56 | +-- FileNotFoundError 57 | +-- InterruptedError 58 | +-- IsADirectoryError 59 | +-- NotADirectoryError 60 | +-- PermissionError 61 | +-- ProcessLookupError 62 | +-- TimeoutError 63 +-- ReferenceError 64 +-- RuntimeError 65 | +-- NotImplementedError 66 | +-- RecursionError 67 +-- SyntaxError 68 | +-- IndentationError 69 | +-- TabError 70 +-- SystemError 71 +-- TypeError 72 +-- ValueError 73 | +-- UnicodeError 74 | +-- UnicodeDecodeError 75 | +-- UnicodeEncodeError 76 | +-- UnicodeTranslateError 77 +-- Warning 78 +-- DeprecationWarning 79 +-- PendingDeprecationWarning 80 +-- RuntimeWarning 81 +-- SyntaxWarning 82 +-- UserWarning 83 +-- FutureWarning 84 +-- ImportWarning 85 +-- UnicodeWarning 86 +-- BytesWarning 87 +-- ResourceWarning 88 89 90 import logging 91 92 def foo(s): 93 return 10 / int(s) 94 95 def bar(s): 96 return foo(s) * 2 97 98 def main(): 99 try: 100 bar('0') 101 except Exception as e: 102 print('Error:', e) 103 logging.exception(e) 104 finally: 105 print('finally...') 106 107 main() 108 print('END') 109 110 class FooError(ValueError): 111 pass 112 def foo(s): 113 n = int(s) 114 if n==0: 115 raise FooError('invalid value: %s' % s) 116 return 10/n 117 118 foo('0') 119 120 def foo(s): 121 n = int(s) 122 if n==0: 123 raise ValueError('invalid value:%s' % s) 124 return 10/n 125 126 def bar(): 127 try: 128 foo('0') 129 except ValueError as e: 130 print('ValueError!') 131 # raise 132 raise ValueError('input error!') 133 bar() 134 135 136 #assert会抛出AssertionError:%s 137 def foo(s): 138 n = int(s) 139 assert n != 0, 'n is zero!' 140 return 10/n 141 142 def main(): 143 foo('0') 144 145 main() 146 ''' 147 148 #python -0 err.py #可以关掉assert 149 150 ''' 151 import logging 152 logging.basicConfig(level=logging.INFO) 153 s = '0' 154 n = int(s) 155 logging.info('n = %d' % n) 156 print(10/n) 157 158 import pdb 159 s = '0' 160 n = int(s) 161 pdb.set_trace()#插入一个断点，自动启动pdb 162 print(10/n) 163 '''
1 #mydict.py 2 class Dict(dict): 3 def __init__(self, **kw): 4 super().__init__(**kw) 5 def __getattr__(self, key): 6 try: 7 return self[key] 8 except KeyError: 9 raise AttributeError(r"'Dict' object has no attribute '%s'" % key) 10 def __setattr__(self, key, value): 11 self[key] = value 12 ''' 13 d = Dict(a=1, b=2) 14 print(d['a']) 15 #print(d['1']) 16 17 '''
1 #mydict_test.py 2 import unittest 3 from mydict import Dict 4 5 class TestDict(unittest.TestCase): 6 def test_init(self): 7 d = Dict(a=1, b='test') 8 self.assertEqual(d.a, 1) 9 self.assertEqual(d.b, 'test') 10 self.assertTrue(isinstance(d, dict)) 11 12 def test_key(self): 13 d = Dict() 14 d['key'] = 'value' 15 self.assertEqual(d.key, 'value') 16 17 def test_attr(self): 18 d = Dict() 19 d.key = 'value' 20 self.assertTrue('key' in d) 21 self.assertEqual(d['key'], 'value') 22 23 def test_keyerror(self): 24 d = Dict() 25 with self.assertRaises(KeyError): 26 value = d['empty'] 27 28 def test_attrerror(self): 29 d = Dict() 30 with self.assertRaises(AttributeError): 31 value = d.empty 32 33 #每个测试方法前运行 34 def setUp(self): 35 print('setUp...') 36 #每个测试方法后运行 37 def tearDown(self): 38 print('tearDown...') 39 if __name__ == 'main': 40 unittest.main()
单元测试例子：
1 #error.py 2 # -*- coding: utf-8 -*- 3 import unittest 4 5 class Student(object): 6 def __init__(self, name, score): 7 self.name = name 8 self.score = score 9 def get_grade(self): 10 if self.score > 100 or self.score < 0: 11 raise ValueError 12 13 14 if self.score >= 80: 15 return 'A' 16 if self.score >= 60: 17 return 'B' 18 return 'C' 19 20 21 22 ''' 23 if score > 100: 24 raise Exception(r"score is over %d" % score) 25 self.name = name 26 if score < 0: 27 raise Exception(r"score is negtive %d" % score) 28 else: 29 '''
1 #error_test.py 2 import unittest 3 from error import Student 4 class TestStudent(unittest.TestCase): 5 6 def test_80_to_100(self): 7 s1 = Student('Bart', 80) 8 s2 = Student('Lisa', 100) 9 self.assertEqual(s1.get_grade(), 'A') 10 self.assertEqual(s2.get_grade(), 'A') 11 12 def test_60_to_80(self): 13 s1 = Student('Bart', 60) 14 s2 = Student('Lisa', 79) 15 self.assertEqual(s1.get_grade(), 'B') 16 self.assertEqual(s2.get_grade(), 'B') 17 18 def test_0_to_60(self): 19 s1 = Student('Bart', 0) 20 s2 = Student('Lisa', 59) 21 self.assertEqual(s1.get_grade(), 'C') 22 self.assertEqual(s2.get_grade(), 'C') 23 24 def test_invalid(self): 25 s1 = Student('Bart', -1) 26 s2 = Student('Lisa', 101) 27 with self.assertRaises(ValueError): 28 s1.get_grade() 29 with self.assertRaises(ValueError): 30 s2.get_grade() 31 32 if __name__ == '__main__': 33 unittest.main()
文档测试功能
1 def fact(n): 2 ''' 3 Calculate 1*2*...*n 4 5 >>> fact(1) 6 1 7 >>> fact(10) 8 3628800 9 >>> fact(-1) 10 Traceback (most recent call last): 11 ... 12 ValueError 13 ''' 14 if n < 1: 15 raise ValueError() 16 if n == 1: 17 return 1 18 return n * fact(n - 1) 19 20 if __name__ == '__main__': 21 #只有在命令行直接运行时，才执行doctest 22 import doctest 23 #doctest.testmod是测试模块，verbose默认是False,意思是出错才用提示；True，对错都有执行结果 24 doctest.testmod(verbose=True)