leosan
Registrado: 19 Abr 2012
Mensajes: 730
Ubicación: GRAN CANARIA
|  Publicado: 28/02/2013 7:55 am | | | Título: [SOLUCIONADO] Matriz Bidimensional con uno de más PYTHON 3.x |
| Teóricamente es una matriz de 3x4, pero se "cuela" uno más.
Al correr el código:
| Código: | m=3
n=4
b = [[m]*n for x in range(n)]
for i in range (m):
for j in range (n):
b[i][j]=(i*j+i+j)
print (b[i][j],end=' ')
print ()
print (b)
print () |
Imprime por un lado de forma correcta:
| Código: | 0 1 2 3
1 3 5 7
2 5 8 11 |
Pero al hacer print (b) sale esto otro:
| Código: | [[0, 1, 2, 3], [1, 3, 5, 7], [2, 5, 8, 11], [3, 3, 3, 3]] |
Y la duda es de dónde diablos sale el "cuarto" elemento;[3, 3, 3, 3]. Porque si hago:
| Código: | for j in range (m):
print (b[j])
print ()
print () |
sale de forma correcta:
| Código: | [0, 1, 2, 3]
[1, 3, 5, 7]
[2, 5, 8, 11] |
y no admite range (m+1) para ver al "otro".
Saluditos!. ...
P.D: Ya lo ví :"b = [[m]*n for x in range( n )]". Como n llega a 4 y se ha inicializado a m=3 saldrán n=4 vectores o listas, vamos que n es el número de filas.
La forma correcta, inicializando a cero sería:
| Código: | m=3
n=4
print ('b=[[0] * n for i in range (m)]\n')
b=[[m] * n for i in range (m)]
print (b) #[[0, 0, 0], [0, 0, 0], [0, 0, 0], [0, 0, 0]]
print ()
for i in range (m):
for j in range (n):
b[i][j]=(i+j)
print (b[i][j],end=' ')
print ()
'''
0 1 2 3
1 2 3 4
2 3 4 5
'''
print (b) # [[0, 1, 2, 3], [1, 2, 3, 4], [2, 3, 4, 5]] |
O como tenía inicialmente, sólo que en ese caso la matriz es de 4x4:
| Código: | m=3
n=4
print ('b=[[0] * n for i in range (n)]\n')
b=[[m] * n for i in range (n)]
print (b) #[[0, 0, 0], [0, 0, 0], [0, 0, 0], [0, 0, 0]]
print ()
for i in range (n):
for j in range (n):
b[i][j]=(i+j)
print (b[i][j],end=' ')
print ()
'''
0 1 2 3
1 2 3 4
2 3 4 5
3 4 5 6
'''
print (b) # [[0, 1, 2, 3], [1, 2, 3, 4], [2, 3, 4, 5], [3, 4, 5, 6]] |
Como resumen de pequeñas variantes a la hora de declarar e inicializar:
| Código: | print ('array None: [[None for col in range(5)] for row in range(3)]\n') #inicializa una matriz mxn a None
array = [[None for col in range(5)] for row in range(3)]
print (array)
#[[None, None, None, None, None], [None, None, None, None, None], [None, None, None, None, None]]
print ()
print (' array2D a 0 = [[0 for col in range(5)] for fil in range(3)]\n' ) ##inicializa una matriz mxn a ceros
array2D = [[0 for col in range(5)] for row in range(3)]
print (' array2D')
print (array2D)
'''array2D
[[0, 0, 0, 0, 0], [0, 0, 0, 0, 0], [0, 0, 0, 0, 0]]'''
print ()
m = int(input("Filas: "))
n = int(input("Columnas: "))
'otro array None'
print ('c=[[None]*n for i in range(m)]\n')
c=[[None]*n for i in range(m)]
print (c,'\n')#[[None, None, None, None], [None, None, None, None], [None, None, None, None]]
for i in range (m):
for j in range (n):
c[i][j]=(j-i)
print (c[i][j],end=' ')
print ()
'''
0 1 2 3
-1 0 1 2
-2 -1 0 1
'''
print (c,'\n') #[[0, 1, 2, 3], [-1, 0, 1, 2], [-2, -1, 0, 1]]
print ('c=c=[[0] * n for i in range (m)]\n')
c=[[0] * n for i in range (m)] #inicializa una matriz mxn a ceros
print (c)
for i in range (m):
for j in range (n):
c[i][j]=(i+j+i*j)
print (c[i][j],end=' ')
print ()
print (c)
print ()
print ('a=[] y m a[i].append(i+j)\n')
a=[]
for i in range (m):
a.append([])
for j in range (n):
a[i].append(i+j)
print (a[i][j],end=' ')
print ()
print ()
'''
0 1 2 3
1 2 3 4
2 3 4 5
'''
print ('b=[[0] * n for i in range (m)]\n')
b=[[0] * n for i in range (m)]
print (b) #[[0, 0, 0], [0, 0, 0], [0, 0, 0], [0, 0, 0]]
print ()
for i in range (m):
for j in range (n):
b[i][j]=(i+j)
print (b[i][j],end=' ')
print ()
'''
0 1 2 3
1 2 3 4
2 3 4 5
'''
print (b) # [[0, 1, 2, 3], [1, 2, 3, 4], [2, 3, 4, 5]]
for j in range (m):
print (b[j])
print ()
print ()
'''
[0, 1, 2, 3]
[1, 3, 5, 7]
[2, 5, 8, 11]
'''
print (b)
print ('tabla: [[ 0 for i in range(n) ] for j in range(m)]\n')
tabla= [[ 0 for i in range(n) ] for j in range(m)]
print (tabla) #[[0, 0, 0], [0, 0, 0], [0, 0, 0], [0, 0, 0]]
for i in range (m):
for j in range (n):
tabla[i][j]=(i*j+i+j)
print (tabla[i][j],end=' ')
print ()
'''
0 1 2 3
1 3 5 7
2 5 8 11
'''
print (tabla) # [[0, 1, 2, 3], [1, 3, 5, 7], [2, 5, 8, 11]]
print ()
b=[[None] * n for i in range (m)]
for i in range (m):
for j in range (n):
b[i][j]=(i*j+i+j)
print (b[i][j],end=' ')
print ()
print (b) # [[0, 1, 2, 3], [1, 3, 5, 7], [2, 5, 8, 11]]
print ()
'''
0 1 2 3
1 3 5 7
2 5 8 11
'''
|
Saluditos!, otra vez y perdón por la extensión... |
|
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