# Creates a list containing 5 lists initialized to 0
Matrix = [[0]*5]*5

注意这个简短的表达，请参见@F.J的答案中的完整解释

从技术上讲，您正在尝试对未初始化的数组进行索引。在添加项目之前，必须先用列表初始化外部列表；Python调用此“列表理解”。

# Creates a list containing 5 lists, each of 8 items, all set to 0
w, h = 8, 5
Matrix = [[0 for x in range(w)] for y in range(h)] 

#您现在可以向列表中添加项目：

Matrix[0][0] = 1
Matrix[6][0] = 3 # error! range... 
Matrix[0][6] = 3 # valid

注意，矩阵是“y”地址主，换句话说，“y索引”在“x索引”之前。

print Matrix[0][0] # prints 1
x, y = 0, 6 
print Matrix[x][y] # prints 3; be careful with indexing! 

尽管您可以根据自己的意愿命名它们，但我这样看是为了避免索引中可能出现的一些混淆，如果您对内部和外部列表都使用“x”，并且希望使用非方形矩阵。

如果您想创建一个二维矩阵，其维度由两个变量定义，并使用其所有元素的默认值对其进行初始化。您可以使用以下简单语法

n_rows=3
n_cols=4
aux_matrix= [[1]*n_cols]*n_rows

为便于阅读而重写：

# 2D array/ matrix

# 5 rows, 5 cols
rows_count = 5
cols_count = 5

# create
#     creation looks reverse
#     create an array of "cols_count" cols, for each of the "rows_count" rows
#        all elements are initialized to 0
two_d_array = [[0 for j in range(cols_count)] for i in range(rows_count)]

# index is from 0 to 4
#     for both rows & cols
#     since 5 rows, 5 cols

# use
two_d_array[0][0] = 1
print two_d_array[0][0]  # prints 1   # 1st row, 1st col (top-left element of matrix)

two_d_array[1][0] = 2
print two_d_array[1][0]  # prints 2   # 2nd row, 1st col

two_d_array[1][4] = 3
print two_d_array[1][4]  # prints 3   # 2nd row, last col

two_d_array[4][4] = 4
print two_d_array[4][4]  # prints 4   # last row, last col (right, bottom element of matrix)

这就是词典的用途！

matrix = {}

可以通过两种方式定义键和值：

matrix[0,0] = value

or

matrix = { (0,0)  : value }

结果：

   [ value,  value,  value,  value,  value],
   [ value,  value,  value,  value,  value],
   ...

输入矩阵和打印的用户定义功能

def inmatrix(m,n):
    #Start function and pass row and column as parameter
    a=[] #create a blank matrix
    for i in range(m): #Row input
        b=[]#blank list
        for j in range(n): # column input
            elm=int(input("Enter number in Pocket ["+str(i)+"]["+str(j)+"] ")) #Show Row And column  number 
            b.append(elm) #add value to b list
        a.append(b)# Add list to matrix
    return  a #return Matrix 

def Matrix(a): #function for print Matrix
    for i in range(len(a)): #row
        for j in range(len(a[0])): #column
            print(a[i][j],end=" ") #print value with space
        print()#print a line After a row print

m=int(input("Enter number of row")) #input row
n=int(input("Enter number of column"))
a=inmatrix(m,n) #call input matrix function 

print("Matrix is ... ")

Matrix(a) #print matrix function