基本上我想这样做:
obj = 'str'
type ( obj ) == string
我试着:
type ( obj ) == type ( string )
但这并没有起作用。
还有,其他类型的呢?例如,我无法复制NoneType。
基本上我想这样做:
obj = 'str'
type ( obj ) == string
我试着:
type ( obj ) == type ( string )
但这并没有起作用。
还有,其他类型的呢?例如,我无法复制NoneType。
当前回答
使用str代替string
type ( obj ) == str
解释
>>> a = "Hello"
>>> type(a)==str
True
>>> type(a)
<type 'str'>
>>>
其他回答
我用type(x) == type(y)
例如,如果我想检查一个数组:
type( x ) == type( [] )
字符串检查:
type( x ) == type( '' ) or type( x ) == type( u'' )
如果您想检查None,请使用is
x is None
要获取类型,使用__class__成员,如unknown_thing.__class__
Talk of duck-typing is useless here because it doesn't answer a perfectly good question. In my application code I never need to know the type of something, but it's still useful to have a way to learn an object's type. Sometimes I need to get the actual class to validate a unit test. Duck typing gets in the way there because all possible objects have the same API, but only one is correct. Also, sometimes I'm maintaining somebody else's code, and I have no idea what kind of object I've been passed. This is my biggest problem with dynamically typed languages like Python. Version 1 is very easy and quick to develop. Version 2 is a pain in the buns, especially if you didn't write version 1. So sometimes, when I'm working with a function I didn't write, I need to know the type of a parameter, just so I know what methods I can call on it.
这就是__class__参数派上用场的地方。这(据我所知)是获取对象类型的最佳方法(可能是唯一的方法)。
因为type返回一个对象,所以可以使用object.name访问对象的名称
例子:
years = 5
user = {'name':'Smith', 'age':20}
print(type(a).__name__)
输出:“int”
print(type(b).__name__ )
输出:“东西”
我想这个就可以了
if isinstance(obj, str)
对于其他类型,请查看types模块:
>>> import types
>>> x = "mystring"
>>> isinstance(x, types.StringType)
True
>>> x = 5
>>> isinstance(x, types.IntType)
True
>>> x = None
>>> isinstance(x, types.NoneType)
True
注:类型检查是个坏主意。