blocks|key|152530|text|创建一个类并为其提供一个__init__方法：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|152531|class+Student:
++++def+__init__(self,+name,+age,+major):
++++++++self.name+=+name
++++++++self.age+=+age
++++++++self.major+=+major

++++def+is_old(self):
++++++++return+self.age+>+100|code-block|syntax|javascript|152532|现在，您可以初始化Student类的一个实例：|152533|>>>+s+=+Student('John',+88,+None)
>>>+s.name
++++'John'
>>>+s.age
++++88|152534|虽然我不确定如果它和Student.__init__做同样的事情，为什么还需要一个make_student学生函数。|152535|entityMap^0|C|8|0|0|9|7|0|0|A|G|15|C|0^^$0|@$1|2|3|4|5|6|7|S|8|@$9|T|A|U|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|V|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|W|8|@$9|X|A|Y|B|C]]|D|@]|E|$]]|$1|M|3|N|5|H|7|Z|8|@]|D|@]|E|$I|J]]|$1|O|3|P|5|6|7|10|8|@$9|11|A|12|B|C]|$9|13|A|14|B|C]]|D|@]|E|$]]|$1|Q|3|-4|5|6|7|15|8|@]|D|@]|E|$]]]|R|$]]

Create a class and give it an <code>__init__</code> method:

<pre><code>class Student:
 def __init__(self, name, age, major):
 self.name = name
 self.age = age
 self.major = major

 def is_old(self):
 return self.age &gt; 100
</code></pre>

Now, you can initialize an instance of the <code>Student</code> class:

<pre><code>&gt;&gt;&gt; s = Student('John', 88, None)
&gt;&gt;&gt; s.name
 'John'
&gt;&gt;&gt; s.age
 88
</code></pre>

Although I'm not sure why you need a <code>make_student</code> student function if it does the same thing as <code>Student.__init__</code>.

blocks|key|370821|text|对象是类的实例。类只是对象的蓝图。所以根据你的类定义-|type|unstyled|depth|inlineStyleRanges|entityRanges|data|370822|#+Note+the+added+(object)+-+this+is+the+preferred+way+of+creating+new+classes
class+Student(object):
++++name+=+"Unknown+name"
++++age+=+0
++++major+=+"Unknown+major"|code-block|syntax|javascript|370823|您可以通过将属性显式分配给Student的新实例来创建make_student函数-|offset|length|style|CODE|370824|def+make_student(name,+age,+major):
++++student+=+Student()
++++student.name+=+name
++++student.age+=+age
++++student.major+=+major
++++return+student|370825|但是在构造函数(__init__)中做这件事可能更有意义--|370826|class+Student(object):
++++def+__init__(self,+name="Unknown+name",+age=0,+major="Unknown+major"):
++++++++self.name+=+name
++++++++self.age+=+age
++++++++self.major+=+major|370827|当您使用Student()时，将调用该构造函数。它将接受__init__方法中定义的参数。构造函数签名现在本质上是Student(name,+age,+major)。|370828|如果您使用它，那么make_student函数是微不足道的(并且是多余的)-|370829|def+make_student(name,+age,+major):
++++return+Student(name,+age,+major)|370830|为了有趣，这里有一个如何在不定义类的情况下创建make_student函数的示例。请不要在家里尝试。|370831|def+make_student(name,+age,+major):
++++return+type('Student',+(object,),
++++++++++++++++{'name':+name,+'age':+age,+'major':+major})()|370832|entityMap^0|0|0|D|7|R|C|0|0|8|8|0|0|4|9|S|8|1L|P|0|9|C|0|0|N|C|0|0^^$0|@$1|2|3|4|5|6|7|14|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|15|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|16|8|@$I|17|J|18|K|L]|$I|19|J|1A|K|L]]|9|@]|A|$]]|$1|M|3|N|5|D|7|1B|8|@]|9|@]|A|$E|F]]|$1|O|3|P|5|6|7|1C|8|@$I|1D|J|1E|K|L]]|9|@]|A|$]]|$1|Q|3|R|5|D|7|1F|8|@]|9|@]|A|$E|F]]|$1|S|3|T|5|6|7|1G|8|@$I|1H|J|1I|K|L]|$I|1J|J|1K|K|L]|$I|1L|J|1M|K|L]]|9|@]|A|$]]|$1|U|3|V|5|6|7|1N|8|@$I|1O|J|1P|K|L]]|9|@]|A|$]]|$1|W|3|X|5|D|7|1Q|8|@]|9|@]|A|$E|F]]|$1|Y|3|Z|5|6|7|1R|8|@$I|1S|J|1T|K|L]]|9|@]|A|$]]|$1|10|3|11|5|D|7|1U|8|@]|9|@]|A|$E|F]]|$1|12|3|-4|5|6|7|1V|8|@]|9|@]|A|$]]]|13|$]]

Objects are instances of classes. Classes are just the blueprints for objects. So given your class definition -

<pre><code># Note the added (object) - this is the preferred way of creating new classes
class Student(object):
 name = "Unknown name"
 age = 0
 major = "Unknown major"
</code></pre>

You can create a <code>make_student</code> function by explicitly assigning the attributes to a new instance of <code>Student</code> -

<pre><code>def make_student(name, age, major):
 student = Student()
 student.name = name
 student.age = age
 student.major = major
 return student
</code></pre>

But it probably makes more sense to do this in a constructor (<code>__init__</code>) -

<pre><code>class Student(object):
 def __init__(self, name="Unknown name", age=0, major="Unknown major"):
 self.name = name
 self.age = age
 self.major = major
</code></pre>

The constructor is called when you use <code>Student()</code>. It will take the arguments defined in the <code>__init__</code> method. The constructor signature would now essentially be <code>Student(name, age, major)</code>.

If you use that, then a <code>make_student</code> function is trivial (and superfluous) -

<pre><code>def make_student(name, age, major):
 return Student(name, age, major)
</code></pre>

For fun, here is an example of how to create a <code>make_student</code> function without defining a class. Please do not try this at home.

<pre><code>def make_student(name, age, major):
 return type('Student', (object,),
 {'name': name, 'age': age, 'major': major})()
</code></pre>

I'm trying to learn python and I now I am trying to get the hang of classes and how to manipulate them with instances.

I can't seem to understand this practice problem:

Create and return a student object whose name, age, and major are
the same as those given as input

<pre><code>def make_student(name, age, major)
</code></pre>

I just don't get what it means by object, do they mean I should create an array inside the function that holds these values? or create a class and let this function be inside it, and assign instances? (before this question i was asked to set up a student class with name, age, and major inside)

<pre><code>class Student:
 name = "Unknown name"
 age = 0
 major = "Unknown major"
</code></pre>

Python, creating objects

我正在尝试学习python，现在我正在尝试掌握类的诀窍，以及如何使用实例来操作它们。我似乎不能理解这个练习问题：创建并返回一个学生对象，该对象的姓名、年龄和专业与作为输入提供的相同def make_student(name, age, major)我只是不明白对象是什么意思，他们的意思是我应该在保存这些值的函数中创建一...

问Python，创建对象
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