Recursive programming stump?
<p>I was asked to create a program, after i was done i was to make a recursive version of it.
Its nothing much, it laces strings together. Here is the version of it that i wrote, can anyone tell me how to make a recursive program out of this?</p>

<pre><code>def laceStrings(s1, s2):
    """
    s1 and s2 are strings.

    Returns a new str with elements of s1 and s2 interlaced,
    beginning with s1. If strings are not of same length, 
    then the extra elements should appear at the end.
    """
    join = []
    smaller = min(s1, s2, key=len)
    for num in range(len(smaller)):
        join.append(s1[num])
        join.append(s2[num])
    join = ''.join(join)
    if len(s1) != len(s2):
        smaller = len(smaller)
        join = join + max(s1, s2, key=len)[smaller:]
    return join
</code></pre>

<p>Edit: My friend gave me this template, but i still cant figure out out. Can anyone help?</p>

<pre><code>def laceStringsRecur(s1, s2):
    """
    s1 and s2 are strings.

    Returns a new str with elements of s1 and s2 interlaced,
    beginning with s1. If strings are not of same length, 
    then the extra elements should appear at the end.
    """
    def helpLaceStrings(s1, s2, out):
        if s1 == '':
            #PLACE A LINE OF CODE HERE
        if s2 == '':
            #PLACE A LINE OF CODE HERE
        else:
            #PLACE A LINE OF CODE HERE
    return helpLaceStrings(s1, s2, '')
</code></pre>
