对角读取文件并让对角字符创建一个列表

Question

I need to read a file containing information on different lines - for example the file may contain

12345678910
abcdefghij
zyxwvutsrq

I will then need to read the code diagonally so my list would be:

(1bx)(2cw)(3dv)

I have tried using zip and just can't figure out a way to get it to work.

EDIT

Is there anyway to also make it take into account the diagonals before the top left corner for example:

(ay)(z) 

in the example file I used.

Edit 2: this is my almost complete code

with open(FileName) as diagonal :
    a = diagonal.read().splitlines()
    l = [a[i][i:] for i in range(len(a))]
    Diaglist = [''.join(i) for i in zip(*l)]

with open(FileName) as diagonal1 :
    b = diagonal1.read().splitlines()
    o = [b[i][:i] for i in range(len(b))]
    Diaglist1 = [''.join(i) for i in zip(*o)]

When I run the file I get the correct diagonals for the first with so from the top right to left but the second with so from the top right downwards I just get an empty list.

Answer 1

Do you mean:

>>> with open('file') as f:
...     l = f.read().splitlines()
>>> l
['12345678910', 'abcdefghij', 'zyxwvutsrq']

>>> l = [l[0]] + [l[1][1:]] + [l[2][2:]]  # remove 'a' from `l[1]` and `zy` from `l[2]`
>>> l
['12345678910', 'bcdefghij', 'xwvutsrq']

>>> list(zip(*l))  # zip them
[('1', 'b', 'x'), ('2', 'c', 'w'), ('3', 'd', 'v'), ('4', 'e', 'u'), ('5', 'f', 't'), ('6', 'g', 's'), ('7', 'h', 'r'), ('8', 'i', 'q')]

>>> [''.join(i) for i in list(zip(*l))]  # also join them
['1bx', '2cw', '3dv', '4eu', '5ft', '6gs', '7hr', '8iq']
>>> 

---

If you don't know how many lines in your file, we can use some magic code like [a[i][i:] for i in range(len(a))] .

Try:

with open('file') as f:
    a = f.read().splitlines()

l = [a[i][i:] for i in range(len(a))]
final_list = [''.join(i) for i in zip(*l)]

print(final_list)

---

As your edit, you can change a[i][i:] to a[i][:i] . Very simple:

with open('file') as f:
    a = f.read().splitlines()

l = [a[i][:i] for i in range(len(a))]
final_list = [''.join(i) for i in zip(*l)][1:]  # since the first element in the list will be empty (`''`), remove it. 

print(final_list)

Answer 2

The following will work for an arbitrary number of lines of the same length , and wraps the final diagonals . This may not be what you want.

def diagonals(lines):
    size = len(lines[0])
    positions = [[(i + x) % size for x in range(len(lines))] 
                 for i in range(size)]
    return ["".join([lines[i][p] for i, p in enumerate(posn)]) 
            for posn in positions]

>>> print(diagonals(['1234567891', 'abcdefghij', 'zyxwvutsrq']))
['1bx', '2cw', '3dv', '4eu', '5ft', '6gs', '7hr', '8iq', '9jz', '1ay']