def get_difference_str(curr, old):
    """
    Returns the formatted string containing difference in counts from yesterday.

    Parameters:
        curr(str): current count.

        old(str): old(yesterday's) count.

    Returns:
        string(str): formatted string.
    """

    curr_num = int(curr)
    old_num = int(old)
    diff = curr_num - old_num

    if(diff == curr_num):
        string = str(curr) + " (+" + str(0) + ")"
    elif(diff >= 0):
        string = str(curr) + " (+" + str(diff) + ")"
    else:
        string = str(curr) + " (" + str(diff) + ")"
    
    return string