1 字符串拼接 l=[1,2,3,4,5,6,7,8,9] str1='' for i in range (0,9):     a=str(l[i])     str1=str1+a print(str1) 2 循环 L=[1,2,3,4,5,6,7,8,9] a=1 for i in range(1,9):     a=a*10+L[i] print(a) 3 python內建的高阶函数 join list=[1,2,3,4,5,6,7,8,9] l=[] for i in range (0,9):     l.append(str(list[i])) print(''.join(l))