* **`'IsADirectoryError'` and `'PermissionError'` can be risen by any.**

* **`'OSError'` is the parent class of all listed exceptions.**

<file>.seek(0) # Moves to the start of the file.

<file>.seek(offset) # Moves 'offset' chars/bytes from the start.

return type.__new__(cls, name, parents, attrs)

* **New() is a class method that gets called before init(). If it returns an instance of its class, then that instance gets passed to init() as a 'self' argument.**

* **New() can also be called directly, usually from a new() method of a child class (**`def __new__(cls): return super().__new__(cls)`**), in which case init() is not called.**

<li><strong><code class="python hljs"><span class="hljs-string">'a+'</span></code> - Read and write from the end.</strong></li>

<li><strong><code class="python hljs"><span class="hljs-string">'t'</span></code> - Text mode (default).</strong></li>

<li><strong><code class="python hljs"><span class="hljs-string">'b'</span></code> - Binary mode.</strong></li>

<li><strong><code class="python hljs"><span class="hljs-string">'FileNotFoundError'</span></code> can be risen when reading with <code class="python hljs"><span class="hljs-string">'r'</span></code> or <code class="python hljs"><span class="hljs-string">'r+'</span></code>.</strong></li>

<li><strong><code class="python hljs"><span class="hljs-string">'FileExistsError'</span></code> can be risen when writing with <code class="python hljs"><span class="hljs-string">'x'</span></code>.</strong></li>

<li><strong><code class="python hljs"><span class="hljs-string">'IsADirectoryError'</span></code> and <code class="python hljs"><span class="hljs-string">'PermissionError'</span></code> can be risen by any.</strong></li>

<li><strong><code class="python hljs"><span class="hljs-string">'OSError'</span></code> is the parent class of all listed exceptions.</strong></li>

&lt;file&gt;.seek(offset) <span class="hljs-comment"># Moves 'offset' chars/bytes from the start.</span>

&lt;file&gt;.seek(<span class="hljs-number">0</span>, <span class="hljs-number">2</span>) <span class="hljs-comment"># Moves to the end of the file.</span>

&lt;bin_file&gt;.seek(±offset, &lt;anchor&gt;) <span class="hljs-comment"># Anchor: 0 start, 1 current pos., 2 end.</span>

<li><strong>New() is a class method that gets called before init(). If it returns an instance of its class, then that instance gets passed to init() as a 'self' argument.</strong></li>

<li><strong>New() can also be called directly, usually from a new() method of a child class (</strong><code class="python hljs"><span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">__new__</span><span class="hljs-params">(cls)</span>:</span> <span class="hljs-keyword">return</span> super().__new__(cls)</code><strong>), in which case init() is not called.</strong></li>

<div><h3 id="metaclassattribute">Metaclass Attribute</h3><p><strong>Right before a class is created it checks if it has a 'metaclass' attribute defined. If not, it recursively checks if any of his parents has it defined and eventually comes to type().</strong></p><pre><code class="python language-python hljs"><span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">MyClass</span><span class="hljs-params">(metaclass=MyMetaClass)</span>:</span>