在Python开发过程中，经常会遇到各种各样的报错情况，所以了解Python中的各种报错就很有必要。小白最近整理了一下Python中经常遇到的报错情况，并列举了案例，如下表格，还有一些报错情况，待尝试~
| AssertionError | 断言语句失败：当 assert 关键字后的条件为假时，程序运行会停止并抛出 AssertionError 异常 | l1 = ['111a'] assert len(l1)>0 l2 = [] assert len(l2)>0 --------------------------------------------------------------------------- AssertionError Traceback (most recent call last) <ipython-input-4-5d421c3e78d3> in <module> 1 l2 = [] ----> 2 assert len(l2)>0 |
| IndexError | 序列中没有此索引(index):索引超出序列范围会引发此异常 | l1 = ['111a'] l1[1] --------------------------------------------------------------------------- IndexError Traceback (most recent call last) <ipython-input-5-130763729f9e> in <module> 1 l1 = ['111a'] ----> 2 l1[1] IndexError: list index out of range |
| KeyError | 映射中没有这个键:字典中查找一个不存在的关键字时引发此异常 | dict={'张三':"50"} dict["李四"] --------------------------------------------------------------------------- KeyError Traceback (most recent call last) <ipython-input-9-77ca0e0db50c> in <module> 1 dict={'张三':"50"} ----> 2 dict["李四"] KeyError: '李四' |
| AttributeError | 对象没有这个属性:当试图访问的对象属性不存在时抛出的异常 | l1 = ['111a'] l1.len --------------------------------------------------------------------------- AttributeError Traceback (most recent call last) <ipython-input-10-f1db6a9cf562> in <module> 1 l1 = ['111a'] ----> 2 l1.len AttributeError: 'list' object has no attribute 'len' |
| NameError | 未声明/初始化对象 (没有属性):尝试访问一个未声明的变量时，引发此异常 | l1 = ['111a'] l2 = [] l3 --------------------------------------------------------------------------- NameError Traceback (most recent call last) <ipython-input-13-75536776ce4c> in <module> 1 l1 = ['111a'] 2 l2 = [] ----> 3 l3 NameError: name 'l3' is not defined |
| TypeError | 对类型无效的操作:不同类型数据之间的无效操作 | 1+'aaa --------------------------------------------------------------------------- TypeError Traceback (most recent call last) <ipython-input-14-9e5eb69813e3> in <module> ----> 1 1+'aaa' TypeError: unsupported operand type(s) for +: 'int' and 'str' |
| ZeroDivisionError | 除(或取模)零 (所有数据类型)：除法运算中除数为 0 引发此异常 | a = 1/0 --------------------------------------------------------------------------- ZeroDivisionError Traceback (most recent call last) <ipython-input-15-6c16767f6731> in <module> ----> 1 a = 1/0 ZeroDivisionError: division by zero |
| StopIteration | 迭代器没有更多的值 | iterable = iter([1,2]) print(next(iterable)) print(next(iterable)) print(next(iterable)) 1 2 --------------------------------------------------------------------------- StopIteration Traceback (most recent call last) <ipython-input-16-0f9614553e6f> in <module> 2 print(next(iterable)) 3 print(next(iterable)) ----> 4 print(next(iterable)) StopIteration: |
| ImportError | 导入模块/对象失败 | import sy --------------------------------------------------------------------------- ModuleNotFoundError Traceback (most recent call last) <ipython-input-29-1afd4de6e860> in <module> ----> 1 import sy ModuleNotFoundError: No module named 'sy' |
| SyntaxError | Python 语法错误 | for i in range(0,10)): File "<ipython-input-30-3edb23e8bd2e>", line 1 for i in range(0,10)): ^ SyntaxError: invalid syntax |
| ValueError | 传入无效的参数 | #range方法的第三个参数不可为0 for i in range(1, 3, 0): print (i) --------------------------------------------------------------------------- ValueError Traceback (most recent call last) <ipython-input-35-3663a22f4899> in <module> ----> 1 for i in range(1, 3, 0): 2 print (i) ValueError: range() arg 3 must not be zero |
| BaseException | 所有异常的基类 | |
| SystemExit | 解释器请求退出 | |
| KeyboardInterrupt | 用户中断执行(通常是输入^C) | |
| Exception | 常规错误的基类 | |
| GeneratorExit | 生成器(generator)发生异常来通知退出 | |
| StandardError | 所有的内建标准异常的基类 | |
| ArithmeticError | 所有数值计算错误的基类 | |
| FloatingPointError | 浮点计算错误 | |
| OverflowError | 数值运算超出最大限制 | |
| EOFError | 没有内建输入,到达EOF 标记 | |
| EnvironmentError | 操作系统错误的基类 | |
| IOError | 输入/输出操作失败 | |
| OSError | 操作系统错误 | |
| WindowsError | 系统调用失败 | |
| LookupError | 无效数据查询的基类 | |
| MemoryError | 内存溢出错误(对于Python 解释器不是致命的) | |
| UnboundLocalError | 访问未初始化的本地变量 | |
| ReferenceError | 弱引用(Weak reference)试图访问已经垃圾回收了的对象 | |
| RuntimeError | 一般的运行时错误 | |
| NotImplementedError | 尚未实现的方法 | |
| IndentationError | 缩进错误 | |
| TabError | Tab 和空格混用 | |
| SystemError | 一般的解释器系统错误 | |
| UnicodeError | Unicode 相关的错误 | |
| UnicodeDecodeError | Unicode 解码时的错误 | |
| UnicodeEncodeError | Unicode 编码时错误 | |
| UnicodeTranslateError | Unicode 转换时错误 | |
| Warning | 警告的基类 | |
| DeprecationWarning | 关于被弃用的特征的警告 | |
| FutureWarning | 关于构造将来语义会有改变的警告 | |
| OverflowWarning | 旧的关于自动提升为长整型(long)的警告 | |
| PendingDeprecationWarning | 关于特性将会被废弃的警告 | |
| RuntimeWarning | 可疑的运行时行为(runtime behavior)的警告 | |
| SyntaxWarning | 可疑的语法的警告 | |
| UserWarning | 用户代码生成的警告 |
为了更加系统的了解报错的层级情况，下面列出Python中错误的层级结构，以下是 Python 内置异常类的层次结构：
BaseException
+-- SystemExit
+-- KeyboardInterrupt
+-- GeneratorExit
+-- Exception
+-- StopIteration
+-- ArithmeticError
| +-- FloatingPointError
| +-- OverflowError
| +-- ZeroDivisionError
+-- AssertionError
+-- AttributeError
+-- BufferError
+-- EOFError
+-- ImportError
+-- LookupError
| +-- IndexError
| +-- KeyError
+-- MemoryError
+-- NameError
| +-- UnboundLocalError
+-- OSError
| +-- BlockingIOError
| +-- ChildProcessError
| +-- ConnectionError
| | +-- BrokenPipeError
| | +-- ConnectionAbortedError
| | +-- ConnectionRefusedError
| | +-- ConnectionResetError
| +-- FileExistsError
| +-- FileNotFoundError
| +-- InterruptedError
| +-- IsADirectoryError
| +-- NotADirectoryError
| +-- PermissionError
| +-- ProcessLookupError
| +-- TimeoutError
+-- ReferenceError
+-- RuntimeError
| +-- NotImplementedError
+-- SyntaxError
| +-- IndentationError
| +-- TabError
+-- SystemError
+-- TypeError
+-- ValueError
| +-- UnicodeError
| +-- UnicodeDecodeError
| +-- UnicodeEncodeError
| +-- UnicodeTranslateError
+-- Warning
+-- DeprecationWarning
+-- PendingDeprecationWarning
+-- RuntimeWarning
+-- SyntaxWarning
+-- UserWarning
+-- FutureWarning
+-- ImportWarning
+-- UnicodeWarning
+-- BytesWarning
+-- ResourceWarning
