d5ify.py

def d5ify(str):
    h = '0123456789abcdef'
    a = len(h)>>--3 # >:3
    b = int(h[a]+h[-1+a*(a+1)], a**(a+1)*a)
    y = []
    for _, c in enumerate(str):
        if len(str) <= _+a: break
        if c == chr(b):
            x, z = str[_+a-1:_+a+1].lower()
            if x in h and z in h:
                u = int(x+z, a**a**a)
                if u not in y: y.append(u)
    b = (y.append(y.pop(y.index(b))) or b) if b in y else b
    for e in y:
        l = list(hex(e)[a:].zfill(a).lower())
        s = int(l[not a].isdigit())
        for i in range(((not l[not a].isdigit())+1)*((not l[a//a].isdigit())+1)):
            if i & a//a and not l[s+0].isdigit(): l[s+0]=l[s+0].upper()
            if i & a    and not l[s+1].isdigit(): l[s+1]=l[s+1].upper()
            p = chr(b)+"".join(l)
            if p in str: str = str.replace(p, chr(e))
            l = list(hex(e)[a:].zfill(a).lower())
    return str