Merge sort algorithm written in Python
Here:

if len(mslist) &lt; 2:


I would write len(mslist) &lt;= 1 because 1 is the interesting number here.

Here:

int(len(mslist)/2)


just write len(mslist)//2 which is explicit integer division.

Here:

            result.append(left[0])
            left.pop(0)


you can write result.append(left.pop()) since pop returns the element removed.

The elifs in the merge function are not properly aligned.

Notice that the use of the pop method could alter algorithm complexity (because I think that pop is \$O(n)\$). It could be better to use two indices to keep track of the position in the two lists.