Removing duplicate elements from a Python list containing unhashable elements while preserving order?
<p>I have a datastructure like this:</p>

<pre><code>[
[('A', '1'), ('B', '2')],
[('A', '1'), ('B', '2')],
[('A', '4'), ('C', '5')]
]
</code></pre>

<p>And I want to obtain this:</p>

<pre><code>[
[('A', '1'), ('B', '2')],
[('A', '4'), ('C', '5')]
]
</code></pre>

<p>Is there a good way of doing this while preserving order as shown?</p>

<p>Commands for copy-pasting:</p>

<pre><code>sample = []
sample.append([('A', '1'), ('B', '2')])
sample.append([('A', '1'), ('B', '2')])
sample.append([('A', '4'), ('C', '5')])
</code></pre>
