Switch the integer to its opposite in python : <p>I'm wondering if there is some built in function in python that will change whatever the sign of an integer is to its opposite. </p>

<p>example of what I'm looking for:</p>

<pre><code>num = 1
num2 = -2

# where flip() is a hypothetical function

flip(num)
flip(num2)

print(num)
print(num2)

&gt;&gt;&gt; -1
&gt;&gt;&gt; 2
</code></pre>

<p>I know how to create my own function to do this, but it seems there may be a built-in, or some short hand way to go about it.</p>
