使用for循环从用户输入创建列表

Question

I am trying to make loop in python where the user input an array 5 times and store them for each i from 1 to 5 in a[i],but my code didn't work.Here is my code :

import numpy
from numpy import linalg
import numpy as np
for i in range(5):
    u[i]=np.array(input(" "))
    print u[i]

Answer 1

First, you need to tell Python that u is going to be a list. Otherwise u[i] will throw a NameError because you're trying to access u without having defined it.

Then, you need to grow the list dynamically, otherwise u[i] will throw an IndexError because, again, you're trying to reference u[i] before it has been created.

import numpy as np
u = []
for i in range(5):
    u.append(np.array(input(" ")))
    print u[i]