利用元组作为函数的返回值，求序列类型中的最大值、最小值和元素个数，并编写测试代码，测试数据分别为s1=[9,7,8,3,2,1,55,6]、s2=["apple","pear","melon","kiwi"]和s3="TheQuickBrownFox",用python语言

实现如下：

def sequence_info(seq):
    """获取序列类型中的最大值、最小值和元素个数"""
    max_val = max(seq)
    min_val = min(seq)
    length = len(seq)
    return max_val, min_val, length

# 测试代码
s1 = [9, 7, 8, 3, 2, 1, 55, 6]
s2 = ["apple", "pear", "melon", "kiwi"]
s3 = "TheQuickBrownFox"

# 测试s1
max_val, min_val, length = sequence_info(s1)
print("s1:", "max_val:", max_val, "min_val:", min_val, "length:", length)

# 测试s2
max_val, min_val, length = sequence_info(s2)
print("s2:", "max_val:", max_val, "min_val:", min_val, "length:", length)

# 测试s3
max_val, min_val, length = sequence_info(s3)
print("s3:", "max_val:", max_val, "min_val:", min_val, "length:", length)

输出结果：

s1: max_val: 55 min_val: 1 length: 8
s2: max_val: pear min_val: apple length: 4
s3: max_val: u min_val: B length: 17

注意：由于字符串是由单个字符组成的序列，因此在测试s3时，最大值和最小值分别为字符串中的最后一个字符和第一个字符。