python loop 问题

Question

a = ['long','short','long']
b = [2,3,4]
c=[]
for i in a:
for y in b:
if i == 'long':
c.append(-y)

    else:
        c.append(y)
      

print(c)

我想得到 c[-2,3,4]
但是却返回[-2, -3, -4, 2, 3, 4, -2, -3, -4]

Answer 1

你应该想得到 c[-2,3,-4]吧，代码如下，有用请点一下采纳谢谢

a = ['long','short','long']
b = [2,3,4]
c=[]
for i, y in zip(a,b):
    if i == 'long':
        c.append(-y)
    else:
        c.append(y)
print(c)