How to separate each sequence of equal numbers from a string?

You have to think how it's done and write the code - must give to do with regular expressions, or do in a line only with map / reduce techniques - but the explicit code in some lines is well readable:

def separate_digits(line):
    result = []
    chain = ""
    last_digit = None
    for digit in line:
        if last_digit != digit:
            if chain:
                result.append(chain)
            chain = ""
        chain += digit
        last_digit = digit
    result.append(chain)
    return result

And this here is the form in a line with "reduce" - just for entertainment purposes :-) - there is also a didactic example of "not everything that can be done in a line should be done in a row "

reduce((lambda previous, digit: [digit] if not previous else (((previous.__setitem__(-1, previous[-1] + digit) if previous[-1][-1] == digit else previous.append(digit)), previous)[1]) ), list("44445552"), [])

update Look, there's another way using Python's strings to have the complete strip method - maybe easier to understand readable:

def separate_strip(line):
    result = []
    while line:
        digits = (len(line) - len(line.lstrip(line[0]))) * line[0]
        result.append(digits)
        line = line.lstrip(line[0])
    return result

So, in Portuguese it would be: "as long as there are elements in the line: (take the (difference in current line size and line size by removing the digits equal to the first) and add these as many digits as the first to the answer; remove the first digit and the others equal it) "

Note that it is only possible because the strings have the 'lstrip' method, which removes all the last characters from the left side of a string.