如何循环我的2D阵列？

Question

我有一个用这个创建的数组：

numbers = []
for num in range(0,5): 
      nums = []
      for inum in range(0,5):
          nums.append(inum) 

      numbers.append(nums)

如何循环？我试过了for item in len(numbers):，但它没有用。

Answer 1

列表项是可迭代的，不需要获取长度，因为它们将自己分配给第一个带有for..in ..循环的变量;

for item in numbers:
    print "In first list: ", item
    for num in item:
        print "    Getting number: ", num

输出

In first list:  [0, 1, 2, 3, 4]
    Getting number:  0
    Getting number:  1
    Getting number:  2
    Getting number:  3
    Getting number:  4
In first list:  [0, 1, 2, 3, 4]
    Getting number:  0
    Getting number:  1
...

Answer 2

for i in range(5):
    for j in range(5):
        print numbers[i][j]

Answer 3

双循环：

for row in numbers:
    for cell in row:
        print cell,
    print

Answer 4

尝试这个。

[[col for col in range(5)] for row in range(5)]