from functools import reduce # method one:字符串拼接 def method_one(a_list):     num = "".join(map(str,a_list))     return num # method two:循环 def method_two(a_list):     num = 0     for i in a_list:         num = num*10 + int(i)     return num # method three:Python内建的高阶函数 def method_three(a_list):     num = reduce(lambda x,y: str(x) + str(y), a_list)     return num list = [1, 2, 3, 4, 5, 6, 7, 8, 9] print(method_one(list)) print(method_two(list)) print(method_three(list))