How do I check if the following items are in the a list? : <p>I need to check if list f is inside bolsa. Then, i should add f in carteira_acoes.</p>

<pre><code>bolsa = {"ibm": 100.0, "google": 200.0, "microsoft": 100.0, "x": 40.0}
carteira_acoes = [["ibm",10],["google",20]]
f = ["x", 40]
if (f[0]) in bolsa.items():
    carteira_acoes.append(f)
print (carteira_acoes)
</code></pre>
