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POplease help me understanding python object instantiation.
 

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  1. POplease help me understanding python object instantiation.
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    <p>I am not a programmer and I am trying to learn python at the moment. But I am a little confused with the object instantiation. I am thinking Class like a template and object is make(or instantiated) based on the template. <strong>Doesn't that mean once object is created(eg. classinst1 = MyClass() ), change in template shouldn't affect what's in the object?</strong></p> <p>In addition, the below code shows that I could change the class variable "common" but only if I haven't assign a new value to the "common" variable in the object. <strong>If I assign a new value to "common" in my object (say classinst1.common = 99), then change my class variable "common" no longer affect classinst.common value????</strong></p> <p>Can someone please clarify for me why the code below behave such way? Is it common to all OO language or just one of the quirky aspects of python? </p> <p>===============</p> <pre><code>&gt;&gt;&gt; class MyClass(object): ... common = 10 ... def __init__(self): ... self.myvar=3 ... def myfunction(self,arg1,arg2): ... return self.myvar ... &gt;&gt;&gt; classinst1 = MyClass() &gt;&gt;&gt; classinst1.myfunction(1,2) 3 &gt;&gt;&gt; classinst2 = MyClass() &gt;&gt;&gt; classinst2.common 10 &gt;&gt;&gt; classinst1.common 10 &gt;&gt;&gt; MyClass.common = 50 &gt;&gt;&gt; classinst1.common 50 &gt;&gt;&gt; classinst2.common 50 &gt;&gt;&gt; classinst1.common = 99 &gt;&gt;&gt; classinst2.common 50 &gt;&gt;&gt; classinst1.common 99 &gt;&gt;&gt; MyClass.common = 7000 &gt;&gt;&gt; classinst1.common 99 &gt;&gt;&gt; classinst2.common 7000 </code></pre>
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    1. COits pretty common, if a variable in a class doesn't have self in front of it, it is common to all instances of the class
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