SyntaxError in python while using commas : <p><strong>Hi.I am new to python.I caught a syntax error while executing this code:</strong></p>

<pre><code>a="input("Enter a no.")"
print(type(a))
</code></pre>

<p><strong>But if I execute:</strong></p>

<pre><code>a='input("Enter a no.")'
print(type(a))
</code></pre>

<p><strong>Or:</strong></p>

<pre><code>a="input('Enter a no.')"
print(type(a))
</code></pre>

<p><strong>Then no error occurs can someone explain me this.
Thanks in advance.</strong></p>
