python中如何判斷一個變數的資料類型

python中如何判斷一個變數的資料類型？(原創) 收藏
import types
type(x) is types.IntType # 判斷是否int 類型
type(x) is types.StringType #是否string類型
.........

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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 類型
type(x) == type('a') #是否string類型

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使用內嵌函數：

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可以得到一個對象的類型 ，利用type函數：

>>>lst = [1, 2, 3]
>>>type(lst)
<type 'list'>

不僅如此，還可以利用isinstance函數，來判斷一個對象是否是一個已知的類型。

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.).

其第一個參數為對象，第二個為類型名或類型名的一個列表。其傳回值為布爾型。若對象的類型與參數二的類型相同則返回True。若參數二為一個元組，則若物件類型與元組中類型名之一相同即返回True。

>>>isinstance(lst, list)
Trueisinstance(lst, (int, str, list))
True

>>>isinstance(lst, (int, str, list))
True

本文來自CSDN部落格，轉載請標明出處：http://blog.csdn.net/suofiya2008/archive/2010/05/13/5587996.aspx