Run-length encoding tech screen

runlength.py

# https://twitter.com/brainix/status/1358343863354552324

def runlength_encoding(s):
    if s:
        count = 1
        for c1, c2 in zip(s[:-1], s[1:]):
            if c1 == c2:
                count += 1
            else:
                yield c1, count
                count = 1
        yield s[-1], count

print(list(runlength_encoding('aaaabbbcca')))