Exercise 1 solution

    import re
    log = "disk 87% full, cpu 5%, mem 100%"

    print(re.findall(r"\d+(?=%)", log))   # ['87', '5', '100']
    print(re.findall(r"\d+%", log))       # ['87%', '5%', '100%']

(Both lines were run and printed exactly the lists shown.)

Explanation: \d+ takes one or more digits. In the first pattern, (?=%) is a
lookahead: it requires a percent sign next but does not consume it, so the
sign is not part of the result. In the second, the % is an ordinary part of
the pattern, so it is included.