方法1:
a = []
for i in range(3):
a.append([])
for j in range(3):
a[i].append(0)
print(a) # [[0, 0, 0], [0, 0, 0], [0, 0, 0]]
方法2:列表推导式
ans = [[0] * c for _ in range(r)] # r,c分别代表行列
print(ans) #

方法1:
a = []
for i in range(3):
a.append([])
for j in range(3):
a[i].append(0)
print(a) # [[0, 0, 0], [0, 0, 0], [0, 0, 0]]
方法2:列表推导式
ans = [[0] * c for _ in range(r)] # r,c分别代表行列
print(ans) #