我想在Python3中打印由一些字符串分隔的整数变量字符串

Question

我正在尝试打印由一些字符串分隔的3个整数变量。但它给了我一个错误

  

TypeError：+：＆＃39; int＆＃39;不支持的操作数类型和＆＃39; str＆＃39;。

我的尝试：

def unpack_values(grades):
     first, *middle, last = grades
     avg = sum(middle)/len(middle)
     print(str(first)+"-------"+str(avg)+" ---- "+str(last))

unpack_values(['10', '20', '30', '40', '50'])

Answer 1

尝试计算sum(middle)时发生错误，因为middle是字符串列表。您需要先将其转换为整数。

In [1]: def unpack_values(grades):
   ...:     first, *middle, last = [int(g) for g in grades]
   ...:     avg = sum(middle) / len(middle)
   ...:     print('{} ------ {} ------ {}'.format(first, avg, last))
   ...:     

In [2]: unpack_values(['10', '20', '30', '40', '50'])
10 ------ 30.0 ------ 50