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    <p>Well, let me try to explain with some images.</p> <p>In Python, everything is an object. Those objects are <em>referenced</em> by variables. Some kinds of objects, such as lists and tuples, just store references to other objects.</p> <p>That said, when you execute</p> <pre><code>myVar = ["jhhj", "hgc"] myTuple = ([1,2,3], [4,5,6], myVar) </code></pre> <p>You get more or less this scenario:</p> <p><img src="https://i.imgur.com/X5ZpQ.png" alt="A tuple pointing to three lists; a list pointing to two strings"></p> <p>Each object is represented by a box/rectangle. We have two string objects, <code>"jhhj"</code> and <code>"hgc"</code>. Also, we have a list object, pointed by the variable <code>myVar</code>; this list object points to both string objects. Also, we have a tuple object, referenced by <code>myTuple</code>; this tuple object points two other lists and the list referenced by <code>myVar</code>.</p> <p>When you execute</p> <pre><code>myVar.append('lololol') </code></pre> <p>what does happen? Well, the list object (that is incidentally pointed by <code>myVar</code>) starts to referenced one more value, the string object <code>"lololol"</code>:</p> <p><img src="https://i.imgur.com/5KrCJ.png" alt="A tuple pointing to three lists; a list pointing to two strings; a new string is added to the list"></p> <p>Note that <code>myVar</code> still references the list object. What happened is that the list object <em>changed</em>. You can look at this list object both from <code>myVar</code> or from the tuple, you will see the same object with the same change.</p> <p>OTOH, when you execute </p> <pre><code>myVar = "lol" myTuple = ([1,2,3], [4,5,6], myVar) </code></pre> <p>You get something like this:</p> <p><img src="https://i.imgur.com/oCJij.png" alt="A tuple pointing to two lists and a string, also pointed by a variable"></p> <p>Now <code>myVar</code> points to the string object <code>"lol"</code>, as well the tuple references it at its third position. Now, if you execute</p> <pre><code>myVar = "lolol" </code></pre> <p>you are just making <code>myVar</code> to point to another object. The tuple object still points to <code>"lol"</code> as before:</p> <p><img src="https://i.imgur.com/HcbyJ.png" alt="A tuple pointing to two lists and a string, also pointed by a variable. The variable now references another string."></p> <p>So, if you attribute a new value to a variable, it will just change the value pointed by this variable. The previous value referenced by the variable will still exist* and any other variable or object pointing to it will stay pointing to it. Just the attributed variable will change.</p> <p>PS: Also, <a href="https://stackoverflow.com/questions/10748158/why-does-the-operator-not-change-a-list-while-append-does/10748191#10748191">I answered a vaguely related question some time ago</a>. You may find the answer helpful.</p> <p>* Except if it is collected by the garbage collector, but this is another long history.</p>
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    1. POWhy does the content of a tuple changes when I append to a list inside of it but does not change when I update a variable?
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