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：abccbadef is_symmetrical(str):length = len(str)for index in range(length / 2):if str[index] == str[length - index - 1]:passelse:return Falsereturn 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1def is_asc(sequence, index):if index > len(sequence) - 1:return Trueif sequence[index] > sequence[index - 1]:return is_asc(sequence, index + 1)return Falseif __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