Sum of all arguments
<p>This is a codewars challenge where you have to return the sum of the given arguments.</p>
<p>Instructions:</p>
<blockquote>
<p>Calculate the sum of all the arguments passed to a function.</p>
<p>Note: If any of the arguments is not a finite number the function should return false/False instead of the sum of the arguments.</p>
</blockquote>
<p>Here's my code:</p>
<pre><code>def sum_all(*args):
    sum = 0

    for str(num) in args:
        if not num.isdigit():
            return False
        else:
            int(sum) += num
    return sum
</code></pre>
<p>Currently I'm getting this error:</p>
<pre><code>File &quot;&quot;, line 9
SyntaxError: can't assign to function call
</code></pre>