def convert_base(n, b):
    """ convert_base(integer, integer) -> string
        Return the textual representation of n (decimal) in base 2 <= b <= 10
    """
    
    result = ""
    while n!=0:
        digit = n%b
        n = n//b
        result = str(digit) + result

    return result

    #problems: wrong result for n=0, infinite loop for n<0, does not support b > 10