Python內建函數OCT詳解_python

英文文檔：

複製代碼 代碼如下:

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.

說明：

1. 函數功能將一個整數轉換成8進位字串。如果傳入浮點數或者字串均會報錯。

>>> a = oct(10)>>> a'0o12'>>> type(a) # 返回結果類型是字串<class 'str'>>>> oct(10.0) # 浮點數不能轉換成8進位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') # 字串不能轉換成8進位Traceback (most recent call last): File "<pyshell#4>", line 1, in <module>  oct('10')TypeError: 'str' object cannot be interpreted as an integer

2. 如果傳入參數不是整數，則其必須是一個定義了__index__並返回整數函數的類的執行個體對象。

# 未定義__index__函數，不能轉換>>> 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# 定義了__index__函數，但是傳回值不是int類型，不能轉換>>> 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)# 定義了__index__函數，而且傳回值是int類型，能轉換>>> 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'