Python - getting just the difference between strings

Question

What\'s the best way of getting just the difference from two multiline strings?

a = \'testing this is working \\n testing this is working 1 \\n\'
b = \'testi         


        

Answer 1

You could use the following function:

def __slave(a, b):

    for i, l_a in enumerate(a):
        if b == l_a:
            return i
    return -1

def diff(a, b):

    t_b = b
    c_i = 0
    for c in a:

        t_i = __slave(t_b, c)
        if t_i != -1 and (t_i > c_i or t_i == c_i):
            c_i = t_i
            t_b = t_b[:c_i] + t_b[c_i+1:]

    t_a = a
    c_i = 0
    for c in b:

        t_i = __slave(t_a, c)
        if t_i != -1 and (t_i > c_i or t_i == c_i):
            c_i = t_i
            t_a = t_a[:c_i] + t_a[c_i+1:]

    return t_b + t_a

Usage sample print diff(a, b)