Return input value inside a function : <p>I need help if someone types a wrong input it should return the question again in python3.</p>

<p>I tried to return the variable.</p>

<pre><code>def main():
    this = input ('Is this your ..? (Yes/No)')
    if this != 'Yes' and this != 'No':
        print ('please provide a valid answer')
</code></pre>

<p>I want to ask the question again and again until the answer will be Yes or No.</p>
