解析python部分常用操作
阿新 • • 發佈:2019-01-11
1 def __add__(self, *args, **kwargs): # real signature unknown 2 """ Return self+value. """ 3 pass
返回相加數值
1 def __alloc__(self): # real signature unknown; restored from __doc__ 2 """ 3 B.__alloc__() -> int 4 5 Return the number of bytes actually allocated.6 """ 7 return 0
返回實際佔用位元組數
1 def __eq__(self, *args, **kwargs): # real signature unknown 2 """ Return self==value. """ 3 pass
相當於==
1 def __ge__(self, *args, **kwargs): # real signature unknown 2 """ Return self>=value. """ 3 pass
相當於 >=
1 def __gt__(self, *args, **kwargs): # real signature unknown 2 """ Return self>value. """ 3 pass
判斷self是否大於 為真返回True,假返回False
1 def __abs__(self, *args, **kwargs): # real signature unknown 2 """ abs(self) """ 3 pass
實現了內建函式abs() 取絕對值
1 def __bool__(self, *args, **kwargs): # real signature unknown 2 """ self != 0 """ 3 pass
判斷是否不等於0 為真返回True,假返回False
1 def __divmod__(self, *args, **kwargs): # real signature unknown 2 """ Return divmod(self, value). """ 3 pass
實現了內建函式divmod 取兩個值的除數和餘數運算結果結合起來,返回一個包含商和餘數的元組(a // b, a % b)。
1 def __float__(self, *args, **kwargs): # real signature unknown 2 """ float(self) """ 3 pass
實現了內建float函式 float()函式用於將整數和字串轉換成浮點數。
1 def __floordiv__(self, *args, **kwargs): # real signature unknown 2 """ Return self//value. """ 3 pass
相當於除 取整數 int
1 def __format__(self): # real signature unknown; restored from __doc__ 2 """ 3 complex.__format__() -> str 4 5 Convert to a string according to format_spec. 6 """ 7 return ""
我自己的理解是預設呼叫時 例如
a="a"
b = a.__format__(str(4))
print(b) # b="a "
print(len(b)) #
類似於format 預設以空格連線
下面是其他人的呼叫方法將__format__重寫 使其拼接的不是空格
__format__()傳參方法:someobject.__format__(specification)
specification為指定格式,當應用程式中出現"{0:specification}".format(someobject)或format(someobject, specification)時,會預設以這種方式呼叫
當specification為" "時,一種合理的返回值是return str(self),這為各種物件的字串表示形式提供了明確的一致性
注意,"{0!s}".format()和"{0!r}".format()並不會呼叫__format__()方法,他們會直接呼叫__str__()或者__repr__()
1 def __getattribute__(self, *args, **kwargs): # real signature unknown 2 """ Return getattr(self, name). """ 3 pass
實習了getattr 函式用於返回一個物件屬性值。可以設定預設值
def __getnewargs__(self, *args, **kwargs): # real signature unknown pass
取出系列化恢復後的狀態
1 def __hash__(self, *args, **kwargs): # real signature unknown 2 """ Return hash(self). """ 3 pass
__hash__方法就是將其id/16取整後作為integer返回
1 def __init__(self, real, imag=None): # real signature unknown; restored from __doc__ 2 pass
初始化一個例項
1 def __int__(self, *args, **kwargs): # real signature unknown 2 """ int(self) """ 3 pass
內建函式int
1 def __le__(self, *args, **kwargs): # real signature unknown 2 """ Return self<=value. """ 3 pass
相當於小於等於只能返回