First solution in Clear category for Long Repeat by
from itertools import groupby
return max((sum(1 for _ in g) for k, g in groupby(line)), default=0)
if __name__ == '__main__':
#These "asserts" using only for self-checking and not necessary for auto-testing
assert long_repeat('sdsffffse') == 4, "First"
assert long_repeat('ddvvrwwwrggg') == 3, "Second"
print('"Run" is good. How is "Check"?')
Aug. 11, 2017