Question

How to declare, initialize and print a matrix in Python

Answer 1

matrix = [[1, 2, 3],
          [4, 5, 6],
          [7, 8, 9]]

for n in matrix:
    print(n)
 
'''
run:
 
[1, 2, 3]
[4, 5, 6]
[7, 8, 9]
 
'''

 

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Answer 2

matrix = []
for i in range(0, 3 + 1):
    row = []
    for j in range(1, 4 + 1):
        row.append(i * j)
    matrix.append(row)

for n in matrix:
    print(n)
 
'''
run:
 
[0, 0, 0, 0]
[1, 2, 3, 4]
[2, 4, 6, 8]
[3, 6, 9, 12]
 
'''

 

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Answer 3

matrix = [[1 for i in range(10)] for j in range(10)]

for n in matrix:
    print(n)
 
'''
run:
 
[1, 1, 1, 1, 1, 1, 1, 1, 1, 1]
[1, 1, 1, 1, 1, 1, 1, 1, 1, 1]
[1, 1, 1, 1, 1, 1, 1, 1, 1, 1]
[1, 1, 1, 1, 1, 1, 1, 1, 1, 1]
[1, 1, 1, 1, 1, 1, 1, 1, 1, 1]
[1, 1, 1, 1, 1, 1, 1, 1, 1, 1]
[1, 1, 1, 1, 1, 1, 1, 1, 1, 1]
[1, 1, 1, 1, 1, 1, 1, 1, 1, 1]
[1, 1, 1, 1, 1, 1, 1, 1, 1, 1]
[1, 1, 1, 1, 1, 1, 1, 1, 1, 1]
 
'''

 

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Answer 4

matrix = [[1, 2, 3],
          [4, 5, 6],
          [7, 8, 9]]

print('\n'.join([''.join(['{:3}'.format(item) for item in row]) for row in matrix]))
 
'''
run:
 
  1  2  3
  4  5  6
  7  8  9
 
'''

 

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Answer 5

matrix = [[1, 2, 3],
          [4, 5, 6],
          [7, 8, 9]]

for i in range(3):
    for j in range(3):
        print('{:3}'.format(matrix[i][j]), end="")
    print()
 
'''
run:
 
  1  2  3
  4  5  6
  7  8  9
 
'''

 

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Answer 6

matrix = [[1, 2, 3],
          [4, 5, 6],
          [7, 8, 9]]

for row in matrix:
    for val in row:
        print('{:3}'.format(val), end="")
    print()
 
'''
run:
 
  1  2  3
  4  5  6
  7  8  9
 
'''

 

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