Python内置bin函数详细介绍
英文文档:
bin(x)
Convert an integer number to a binary string. The result is a valid Python expression. If x is not a Python int object, it has to define an __index__() method that returns an integer.
说明:
1. 将一个整形数字转换成二进制字符串
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>>> b = bin(3) >>> b'0b11'>>> type(b) #获取b的类型<class></class>
2. 如果参数x不是一个整数,则x必须定义一个 __index__() 方法,并且方法返回值必须是整数。
2.1 如果对象不是整数,则报错
>>> class A: pass>>> a = A()>>> bin(a) Traceback (most recent call last): File "<pyshell>", line 1, in <module> bin(a)TypeError: 'A' object cannot be interpreted as an integer</module></pyshell>
2.2 如果对象定义了__index__方法,但返回值不是整数,报错
>>> class B: def __index__(self): return "3">>> b = B()>>> bin(b)Traceback (most recent call last): File "<pyshell>", line 1, in <module> bin(b)TypeError: __index__ returned non-int (type str)</module></pyshell>
2.3 对象定义了__index__方法,且返回值是整数,将__index__方法返回值转换成二进制字符串
>>> class C: def __index__(self): return 3>>> c = C()>>> bin(c)'0b11'