python如何判斷資料型別
python中如何判斷一個變數的資料型別?(原創) 收藏
import types
type(x) is types.IntType # 判斷是否int 型別
type(x) is types.StringType #是否string型別
.........
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超級噁心的模式,不用記住types.StringType
import types
type(x) == types(1) # 判斷是否int 型別
type(x) == type('a') #是否string型別
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使用內嵌函式:
isinstance ( object, classinfo )
Return true if the object argument is an instance of the classinfo argument, or of a (direct or indirect) subclass thereof. Also return true if classinfo is a type object and object is an object of that type. If object is not a class instance or an object of
the given type, the function always returns false. If classinfo is neither a class object nor a type object, it may be a tuple of class or type objects, or may recursively contain other such tuples (other sequence types are not accepted). If classinfo is not
a class, type, or tuple of classes, types, and such tuples, a TypeError exception is raised. Changed in version 2.2: Support for a tuple of type information was added.
Python可以得到一個物件的型別 ,利用type函式:
>>>lst = [1, 2, 3]
>>>type(lst)
<type 'list'>
不僅如此,還可以利用isinstance函式,來判斷一個物件是否是一個已知的型別。
isinstance說明如下:
isinstance(object, class-or-type-or-tuple) -> bool
Return whether an object is an instance of a class or of a subclass thereof.
With a type as second argument, return whether that is the object's type.
The form using a tuple, isinstance(x, (A, B, ...)), is a shortcut for
isinstance(x, A) or isinstance(x, B) or ... (etc.).
其第一個引數為物件,第二個為型別名或型別名的一個列表。其返回值為布林型。若物件的型別與引數二的型別相同則返回True。若引數二為一個元組,則若物件型別與元組中型別名之一相同即返回True。
>>>isinstance(lst, list)
Trueisinstance(lst, (int, str, list))
True
>>>isinstance(lst, (int, str, list))
True