首页 > 编程 > Python > 正文

Python内置函数OCT详解

2019-11-25 16:29:54
字体:
来源:转载
供稿:网友

英文文档:

复制代码 代码如下:
oct ( x )
Convert an integer number to an octal string. The result is a valid Python expression. If x is not a Pythonobject, it has to define anmethod that returns an integer.

说明:

1. 函数功能将一个整数转换成8进制字符串。如果传入浮点数或者字符串均会报错。

>>> a = oct(10)>>> a'0o12'>>> type(a) # 返回结果类型是字符串<class 'str'>>>> oct(10.0) # 浮点数不能转换成8进制Traceback (most recent call last): File "<pyshell#3>", line 1, in <module>  oct(10.0)TypeError: 'float' object cannot be interpreted as an integer>>> oct('10') # 字符串不能转换成8进制Traceback (most recent call last): File "<pyshell#4>", line 1, in <module>  oct('10')TypeError: 'str' object cannot be interpreted as an integer

2. 如果传入参数不是整数,则其必须是一个定义了__index__并返回整数函数的类的实例对象。

# 未定义__index__函数,不能转换>>> class Student:  def __init__(self,name,age):    self.name = name    self.age = age  >>> a = Student('Kim',10)>>> oct(a)Traceback (most recent call last): File "<pyshell#12>", line 1, in <module>  oct(a)TypeError: 'Student' object cannot be interpreted as an integer# 定义了__index__函数,但是返回值不是int类型,不能转换>>> class Student:  def __init__(self,name,age):    self.name = name    self.age = age  def __index__(self):    return self.name>>> a = Student('Kim',10)>>> oct(a)Traceback (most recent call last): File "<pyshell#18>", line 1, in <module>  oct(a)TypeError: __index__ returned non-int (type str)# 定义了__index__函数,而且返回值是int类型,能转换>>> class Student:  def __init__(self,name,age):    self.name = name    self.age = age  def __index__(self):    return self.age>>> a = Student('Kim',10)>>> oct(a)'0o12'

发表评论 共有条评论
用户名: 密码:
验证码: 匿名发表