Write a function grade(s) that given a float score s such that 0≤ s ≤ 10 returns the grade string that corresponds to s. The result of the function has to stick to the catalan grading rules: when s is less than 5 the grade is ’suspens’, when s is at least 5 but less than 7 the grade is ’aprovat’, when s is at least 7 but less than 9 is ’notable’, when s is at least 9 but less than 10 is ’excel.lent’ —note that the dot is the usual one— and finally, if s is 10 the grade is ’MH’.
>>> grade(4.99) 'suspens' >>> grade(8) 'notable' >>> grade(6.99) 'aprovat' >>> grade(9.5) 'excel.lent' >>> grade(10) 'MH'