How I can transfer matrix in Python?

Question

#Example:
A = [[1,2,3,4],[4,3,2,1],[3,2,1,4],[2,1,4,3]]
#How I can transform matrix A become matrix B 
#with matrix B I want to become...
B = [[1],
     [2],
     [3],
     [4],
     [4],
     [3],
     [2],
     [1],
     [3],
     [2],
     [1],
     [4],
     [2],
     [1],
     [4],
     [3]]

And when I save .txt or .csv how I can transfer data without [] in all of the data?

`[[x] for xs in A for x in xs]` https://docs.python.org/3/tutorial/datastructures.html#list-comprehensions — falsetru, Sep 24 '22 at 12:29
**without []** means you want output like this `[1, 2, 3, 4, 4, 3, 2, 1, 3, 2, 1, 4, 2, 1, 4, 3]`? — Ramesh, Sep 24 '22 at 12:32
Please clarify your specific problem or provide additional details to highlight exactly what you need. As it's currently written, it's hard to tell exactly what you're asking. — Community, Sep 24 '22 at 12:36
Sorry, but you can help me exactly code in this case? because it's still not working. — Công Minh Đặng, Sep 24 '22 at 12:38
are you willing to use an appropriate format like JSON instead of txt or csv ? — azro, Sep 24 '22 at 12:41

Ramesh · Answer 1 · 2022-09-24T12:57:32.297

0

using chain

from itertools import  chain
lst = [[1, 2, 3, 4], [4, 3, 2, 1], [3, 2, 1, 4], [2, 1, 4, 3]]
data = [[x] for xs in lst for x in xs]
result = list(chain.from_iterable(data))
print(data)
print(result)

>>> [[1], [2], [3], [4], [4], [3], [2], [1], [3], [2], [1], [4], [2], [1], [4], [3]]
>>> [1, 2, 3, 4, 4, 3, 2, 1, 3, 2, 1, 4, 2, 1, 4, 3]

edited Sep 24 '22 at 12:57

answered Sep 24 '22 at 12:47

Ramesh

635
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How I can save data by one column? – Công Minh Đặng Sep 24 '22 at 12:56
it is already given in above comment by @falsetru. i just edited it – Ramesh Sep 24 '22 at 12:59

Vương Hữu Thiện · Accepted Answer · 2022-09-26T02:01:25.510

0

Write full

A = [[1,2,3,4],[4,3,2,1],[3,2,1,4],[2,1,4,3]]
B = []

for Am in A:
  for x in Am:
    B.append([x])

print (B)

Write short

A = [[1,2,3,4],[4,3,2,1],[3,2,1,4],[2,1,4,3]]
B = [[x] for Am in A for x in Am]
print (B)

Link Example

edited Sep 26 '22 at 02:01

answered Sep 25 '22 at 22:37

Vương Hữu Thiện

1,460
14
21

How I can transfer matrix in Python?

2 Answers2