blocks|key|1446154|text|使用type()内置函数：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1446155|>>>+i+=+123
>>>+type(i)
<type+'int'>
>>>+type(i)+is+int
True
>>>+i+=+123.456
>>>+type(i)
<type+'float'>
>>>+type(i)+is+float
True|code-block|syntax|javascript|1446156|要检查变量是否为给定类型，请使用isinstance|1446157|>>>+i+=+123
>>>+isinstance(i,+int)
True
>>>+isinstance(i,+(float,+str,+set,+dict))
False|1446158|注意，Python不具有与C/C%2B%2B相同的类型，这似乎是您的问题所在。|1446159|entityMap|0|LINK|mutability|MUTABLE|url|https://docs.python.org/library/functions.html#type|1|https://docs.python.org/library/functions.html#isinstance^0|2|6|2|6|0|0|0|G|A|G|A|1|0|0|0^^$0|@$1|2|3|4|5|6|7|10|8|@$9|11|A|12|B|C]]|D|@$9|13|A|14|1|15]]|E|$]]|$1|F|3|G|5|H|7|16|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|17|8|@$9|18|A|19|B|C]]|D|@$9|1A|A|1B|1|1C]]|E|$]]|$1|M|3|N|5|H|7|1D|8|@]|D|@]|E|$I|J]]|$1|O|3|P|5|6|7|1E|8|@]|D|@]|E|$]]|$1|Q|3|-4|5|6|7|1F|8|@]|D|@]|E|$]]]|R|$S|$5|T|U|V|E|$W|X]]|Y|$5|T|U|V|E|$W|Z]]]]

Use the <a href="https://docs.python.org/library/functions.html#type" rel="noreferrer"><code>type()</code></a> builtin function:

<pre><code>&gt;&gt;&gt; i = 123
&gt;&gt;&gt; type(i)
&lt;type 'int'&gt;
&gt;&gt;&gt; type(i) is int
True
&gt;&gt;&gt; i = 123.456
&gt;&gt;&gt; type(i)
&lt;type 'float'&gt;
&gt;&gt;&gt; type(i) is float
True
</code></pre>

To check if a variable is of a given type, use <a href="https://docs.python.org/library/functions.html#isinstance" rel="noreferrer"><code>isinstance</code></a>:

<pre><code>&gt;&gt;&gt; i = 123
&gt;&gt;&gt; isinstance(i, int)
True
&gt;&gt;&gt; isinstance(i, (float, str, set, dict))
False
</code></pre>

Note that Python doesn't have the same types as C/C++, which appears to be your question.

blocks|key|1446264|text|这很简单。你可以这样做。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1446265|print(type(variable_name))|code-block|syntax|javascript|1446266|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

It is so simple. You do it like this.

<pre><code>print(type(variable_name))
</code></pre>

blocks|key|1446028|text|print+type(variable_name)|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1446029|在处理这样的问题时，我也强烈推荐使用IPython交互式解释器。它允许您输入variable_name?，并将返回有关对象的完整信息列表，包括类型和该类型的文档字符串。|unstyled|offset|length|style|CODE|1446030|例如：|1446031|In+[9]:+var+=+123

In+[10]:+var?
Type:+++++++int
Base+Class:+<type+'int'>
String+Form:++++123
Namespace:++Interactive
Docstring:
++++int(x[,+base])+->+integer|1446032|如果可能，将字符串或数字转换为整数。浮点参数将被截断为零(这不包括浮点数的字符串表示！)转换字符串时，请使用可选的base。在转换非字符串时提供基数是错误的。如果参数超出整数范围，将返回一个长对象。|1446033|entityMap|0|LINK|mutability|MUTABLE|url|http://ipython.scipy.org/^0|0|12|E|I|7|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Y|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|Z|8|@$G|10|H|11|I|J]]|9|@$G|12|H|13|1|14]]|A|$]]|$1|K|3|L|5|F|7|15|8|@]|9|@]|A|$]]|$1|M|3|N|5|6|7|16|8|@]|9|@]|A|$B|C]]|$1|O|3|P|5|F|7|17|8|@]|9|@]|A|$]]|$1|Q|3|-4|5|F|7|18|8|@]|9|@]|A|$]]]|R|$S|$5|T|U|V|A|$W|X]]]]

<pre><code>print type(variable_name)
</code></pre>

I also highly recommend the <a href="http://ipython.scipy.org/" rel="noreferrer">IPython</a> interactive interpreter when dealing with questions like this. It lets you type <code>variable_name?</code> and will return a whole list of information about the object including the type and the doc string for the type.

e.g.

<pre><code>In [9]: var = 123

In [10]: var?
Type: int
Base Class: &lt;type 'int'&gt;
String Form: 123
Namespace: Interactive
Docstring:
 int(x[, base]) -&gt; integer
</code></pre>

Convert a string or number to an integer, if possible. A floating point argument will be truncated towards zero (this does not include a string
representation of a floating point number!) When converting a string, use the optional base. It is an error to supply a base when converting a
 non-string. If the argument is outside the integer range a long object
 will be returned instead.

blocks|key|1661258|text|a+=+"cool"
type(a)

//result+'str'
<class+'str'>
or+
do+
`dir(a)`+
to+see+the+list+of+inbuilt+methods+you+can+have+on+the+variable.|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1661259|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>a = "cool"
type(a)

//result 'str'
&lt;class 'str'&gt;
or 
do 
`dir(a)` 
to see the list of inbuilt methods you can have on the variable.
</code></pre>

blocks|key|1661035|text|另一种使用__class__的方法|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1661036|>>>+a+=+[1,+2,+3,+4]
>>>+a.__class__
<type+'list'>
>>>+b+=+{'key1':+'val1'}
>>>+b.__class__
<type+'dict'>
>>>+c+=+12
>>>+c.__class__
<type+'int'>|code-block|syntax|javascript|1661037|entityMap^0|5|9|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

One more way using <code>__class__</code>:

<pre><code>&gt;&gt;&gt; a = [1, 2, 3, 4]
&gt;&gt;&gt; a.__class__
&lt;type 'list'&gt;
&gt;&gt;&gt; b = {'key1': 'val1'}
&gt;&gt;&gt; b.__class__
&lt;type 'dict'&gt;
&gt;&gt;&gt; c = 12
&gt;&gt;&gt; c.__class__
&lt;type 'int'&gt;
</code></pre>

blocks|key|1446291|text|Python中的简单类型检查示例：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1446292|assert+type(variable_name)+==+int

assert+type(variable_name)+==+bool

assert+type(variable_name)+==+list|code-block|syntax|javascript|1446293|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Examples of simple type checking in Python:

<pre><code>assert type(variable_name) == int

assert type(variable_name) == bool

assert type(variable_name) == list
</code></pre>

blocks|key|1446199|text|这可能有点无关紧要。但是你可以像前面提到的here那样用isinstance(object,+type)检查对象的类型。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1446200|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/questions/2225038/python-determine-the-type-of-an-object^0|S|O|L|4|0|0^^$0|@$1|2|3|4|5|6|7|N|8|@$9|O|A|P|B|C]]|D|@$9|Q|A|R|1|S]]|E|$]]|$1|F|3|-4|5|6|7|T|8|@]|D|@]|E|$]]]|G|$H|$5|I|J|K|E|$L|M]]]]

It may be little irrelevant. but you can check types of an object with <code>isinstance(object, type)</code> as mentioned <a href="https://stackoverflow.com/questions/2225038/python-determine-the-type-of-an-object" title="Object type in python">here</a>.

blocks|key|1660827|text|你是指在Python中还是在使用ctypes|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1660828|在第一种情况下，您根本不能-因为Python没有带符号/无符号的16/32位整数。|1660829|在第二种情况下，您可以使用type()|style|CODE|1660830|>>>+import+ctypes
>>>+a+=+ctypes.c_uint()+#+unsigned+int
>>>+type(a)
<class+'ctypes.c_ulong'>|code-block|syntax|javascript|1660831|有关ctype及其类型的更多参考，请参见the+official+documentation。|1660832|entityMap|0|LINK|mutability|MUTABLE|url|http://en.wikipedia.org/wiki/Python_%2528programming_language%2529|1|http://www.python.org/doc/2.5/lib/module-ctypes.html|2|http://docs.python.org/library/ctypes.html^0|4|6|0|G|6|1|0|0|D|6|0|0|K|Q|2|0^^$0|@$1|2|3|4|5|6|7|12|8|@]|9|@$A|13|B|14|1|15]|$A|16|B|17|1|18]]|C|$]]|$1|D|3|E|5|6|7|19|8|@]|9|@]|C|$]]|$1|F|3|G|5|6|7|1A|8|@$A|1B|B|1C|H|I]]|9|@]|C|$]]|$1|J|3|K|5|L|7|1D|8|@]|9|@]|C|$M|N]]|$1|O|3|P|5|6|7|1E|8|@]|9|@$A|1F|B|1G|1|1H]]|C|$]]|$1|Q|3|-4|5|6|7|1I|8|@]|9|@]|C|$]]]|R|$S|$5|T|U|V|C|$W|X]]|Y|$5|T|U|V|C|$W|Z]]|10|$5|T|U|V|C|$W|11]]]]

Do you mean in <a href="http://en.wikipedia.org/wiki/Python_%28programming_language%29" rel="noreferrer">Python</a> or using <a href="http://www.python.org/doc/2.5/lib/module-ctypes.html" rel="noreferrer">ctypes</a>?

In the first case, you simply cannot - because Python does not have signed/unsigned, 16/32 bit integers.

In the second case, you can use <code>type()</code>:

<pre><code>&gt;&gt;&gt; import ctypes
&gt;&gt;&gt; a = ctypes.c_uint() # unsigned int
&gt;&gt;&gt; type(a)
&lt;class 'ctypes.c_ulong'&gt;
</code></pre>

For more reference on ctypes, an its type, see <a href="http://docs.python.org/library/ctypes.html" rel="noreferrer">the official documentation</a>.

blocks|key|1660871|text|Python没有您所描述的类型。有两种类型用于表示整数值：int，它对应于C中平台的int类型，以及long，它是一个任意精度的整数(即它根据需要增长，没有上限)。如果表达式产生的结果不能存储在int中，则long会被静默转换为int。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1660872|entityMap^0|T|3|1E|4|2P|3|2V|4|36|3|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]|$9|K|A|L|B|C]|$9|M|A|N|B|C]|$9|O|A|P|B|C]|$9|Q|A|R|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|S|8|@]|D|@]|E|$]]]|G|$]]

Python doesn't have such types as you describe. There are two types used to represent integral values: <code>int</code>, which corresponds to platform's int type in C, and <code>long</code>, which is an arbitrary precision integer (i.e. it grows as needed and doesn't have an upper limit). <code>int</code>s are silently converted to <code>long</code> if an expression produces result which cannot be stored in <code>int</code>.

blocks|key|1661145|text|简单，适用于python+3.4及更高版本|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1661146|print+(type(variable_name))|code-block|syntax|javascript|1661147|Python+2.7及更高版本|1661148|print+type(variable_name)|1661149|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

Simple, for python 3.4 and above

<pre><code>print (type(variable_name))
</code></pre>

Python 2.7 and above

<pre><code>print type(variable_name)
</code></pre>

blocks|key|1660985|text|这真的取决于你指的是什么水平。在Python2.x中，由于历史原因，有两种整数类型，int+(受限于sys.maxint)和long+(无限精度)。在Python代码中，这不会有什么不同，因为当数字太大时，解释器会自动转换为long。如果您想了解底层解释器中使用的实际数据类型，这取决于实现。(CPython位于Objects/+in+ject.c和Objects/longobject.c中。)要了解有关系统类型的信息，请查看使用struct模块的cdleary答案。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1660986|entityMap^0|16|3|1E|A|1Q|4|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]|$9|K|A|L|B|C]|$9|M|A|N|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|O|8|@]|D|@]|E|$]]]|G|$]]

It really depends on what level you mean. In Python 2.x, there are two integer types, <code>int</code> (constrained to <code>sys.maxint</code>) and <code>long</code> (unlimited precision), for historical reasons. In Python code, this shouldn't make a bit of difference because the interpreter automatically converts to long when a number is too large. If you want to know about the actual data types used in the underlying interpreter, that's implementation dependent. (CPython's are located in Objects/intobject.c and Objects/longobject.c.) To find out about the systems types look at cdleary answer for using the struct module.

blocks|key|1446373|text|对于python2.x，使用|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1446374|print+type(variable_name)|code-block|syntax|javascript|1446375|对于python3.x，使用|1446376|print(type(variable_name))|1446377|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

For python2.x, use 

<pre><code>print type(variable_name)
</code></pre>

For python3.x, use 

<pre><code>print(type(variable_name))
</code></pre>

blocks|key|1661293|text|您应该使用type()函数。如下所示：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1661294|my_variable+=+5

print(type(my_variable))+#+Would+print+out+<class+'int'>|code-block|syntax|javascript|1661295|此函数将查看任何变量的类型，无论是列表还是类。有关更多信息，请访问以下网站：https://www.w3schools.com/python/ref_func_type.asp|1661296|entityMap|0|LINK|mutability|MUTABLE|url|https://www.w3schools.com/python/ref_func_type.asp^0|5|6|0|0|12|1E|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@$9|V|A|W|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|X|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|Y|8|@]|D|@$9|Z|A|10|1|11]]|E|$]]|$1|M|3|-4|5|6|7|12|8|@]|D|@]|E|$]]]|N|$O|$5|P|Q|R|E|$S|T]]]]

You should use the <code>type()</code> function. Like so:
<pre><code>my_variable = 5

print(type(my_variable)) # Would print out &lt;class 'int'&gt;
</code></pre>
This function will view the type of any variable, whether it's a list or a class. Check this website for more information: <a href="https://www.w3schools.com/python/ref_func_type.asp" rel="noreferrer">https://www.w3schools.com/python/ref_func_type.asp</a>

blocks|key|1661378|text|没有32位、64位和16位，python很简单，你不用担心。请参阅如何检查类型：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1661379|integer+=+1
print(type(integer))++#+Result:+<class+'int'>,+and+if+it's+a+string+then+class+will+be+str+and+so+on.

#+Checking+the+type
float_class+=+1.3
print(isinstance(float_class,+float))++#+True|code-block|syntax|javascript|1661380|但是如果你真的必须这样做，你可以使用Ctypes库，它的类型像无符号整数。|offset|length|1661381|Ctypes+types+documentation|1661382|你可以这样使用它：|1661383|from+ctypes+import+*
uint+=+c_uint(1)++#+Unsigned+integer
print(uint)++#+Output:+c_uint(1)

#+To+actually+get+the+value,+you+have+to+call+.value
print(uint.value)

#+Change+value
uint.value+=+2
print(uint.value)++#+2|1661384|entityMap|0|LINK|mutability|MUTABLE|url|https://docs.python.org/3/library/ctypes.html|1|https://docs.python.org/3/library/ctypes.html#fundamental-data-types^0|0|0|I|6|0|0|0|Q|1|0|0|0^^$0|@$1|2|3|4|5|6|7|10|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|11|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|12|8|@]|9|@$I|13|J|14|1|15]]|A|$]]|$1|K|3|L|5|6|7|16|8|@]|9|@$I|17|J|18|1|19]]|A|$]]|$1|M|3|N|5|6|7|1A|8|@]|9|@]|A|$]]|$1|O|3|P|5|D|7|1B|8|@]|9|@]|A|$E|F]]|$1|Q|3|-4|5|6|7|1C|8|@]|9|@]|A|$]]]|R|$S|$5|T|U|V|A|$W|X]]|Y|$5|T|U|V|A|$W|Z]]]]

There's no 32bit and 64bit and 16bit, python is simple, you don't have to worry about it. See how to check the type:
<pre><code>integer = 1
print(type(integer)) # Result: &lt;class 'int'&gt;, and if it's a string then class will be str and so on.

# Checking the type
float_class = 1.3
print(isinstance(float_class, float)) # True
</code></pre>
But if you really have to, you can use <a href="https://docs.python.org/3/library/ctypes.html" rel="nofollow noreferrer">Ctypes</a> library which has types like unsigned integer.
<a href="https://docs.python.org/3/library/ctypes.html#fundamental-data-types" rel="nofollow noreferrer">Ctypes types documentation</a>
You can use it like this:
<pre><code>from ctypes import *
uint = c_uint(1) # Unsigned integer
print(uint) # Output: c_uint(1)

# To actually get the value, you have to call .value
print(uint.value)

# Change value
uint.value = 2
print(uint.value) # 2
</code></pre>

blocks|key|1661245|text|不要这样做。询问某样东西的类型本身就是错误的。相反，请使用多态性。找到或在必要时自己定义对任何可能的输入类型执行所需操作的方法，并在不询问任何内容的情况下调用它。如果您需要使用内置类型或由第三方库定义的类型，则始终可以从它们继承并使用自己的派生。或者，您可以将它们包装在您自己的类中。这就是解决此类问题的面向对象方法。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1661246|如果你坚持检查确切的类型并在各处放置一些脏的if，你可以使用__class__属性或type函数来做这件事，但很快你就会发现自己每两到三次提交就会用额外的if来更新所有这些提交。使用面向对象的方法可以避免这种情况，只允许您为新的输入类型定义一个新的类。|offset|length|style|CODE|1661247|entityMap^0|0|M|2|U|9|16|4|25|2|0^^$0|@$1|2|3|4|5|6|7|J|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|K|8|@$D|L|E|M|F|G]|$D|N|E|O|F|G]|$D|P|E|Q|F|G]|$D|R|E|S|F|G]]|9|@]|A|$]]|$1|H|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|I|$]]

Just do not do it. Asking for something's type is wrong in itself. Instead use polymorphism. Find or if necessary define by yourself the method that does what you want for any possible type of input and just call it without asking about anything. If you need to work with built-in types or types defined by a third-party library, you can always inherit from them and use your own derivatives instead. Or you can wrap them inside your own class. This is the object-oriented way to resolve such problems.

If you insist on checking exact type and placing some dirty <code>if</code>s here and there, you can use <code>__class__</code> property or <code>type</code> function to do it, but soon you will find yourself updating all these <code>if</code>s with additional cases every two or three commits. Doing it the OO way prevents that and lets you only define a new class for a new type of input instead.

How do I see the type of a variable whether it is unsigned 32 bit, signed 16 bit, etc.?

How do I view it?

How to determine a Python variable's type?

如何查看变量的类型，是否为无符号32位、有符号16位等？我如何查看它？

问如何确定Python变量的类型？
EN

回答 15

Stack Overflow用户

Stack Overflow用户

Stack Overflow用户

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问如何确定Python变量的类型？EN

回答 15

Stack Overflow用户

Stack Overflow用户

Stack Overflow用户

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问如何确定Python变量的类型？
EN