判断一字符串是否对称，如：abccba

# 1.判断一字符串是不是对称的，如：abccba

def is_symmetrical(str):
	length = len(str)
	for index in range(length / 2):
		if str[index] == str[length - index - 1]:
			pass
		else:
			return False
	return True

 if __name__ == "__main__":
         print is_symmertrical("abcdcba"),
         print is_symmertrical("abccaa"),

运行结果: True False

# 2.用递归的方法判断整数组a[N]是不是升序排列

# index初始化为1
def is_asc(sequence, index):
	if index > len(sequence) - 1:
		return True
	if sequence[index] > sequence[index - 1]:
		return is_asc(sequence, index + 1)
	return False

if __name__ == "__main__":
         sequence1 = [1, 100, 100, 200]
         print is_asc(sequence1, 1),
         sequence2 = [1, 100, 101, 500]
         print is_asc(sequence2, 1),

运行结果: False True