How can i create multidimensional list in Python?

问题

How can i create a multidimensional list while iterating through a 1d list based upon some condition.

I am iterating over a 1d list and whenever i find a '\n' i should append the so created list with a new list, for example,

 a = [1,2,3,4,5,'\n',6,7,8,9,0,'\n',3,45,6,7,2]

so I want it to be as,

new_list = [[1,2,3,4],[6,7,8,9,0],[3,45,6,7,2]]

how should i do it? Please help

def storeData(k):
    global dataList
    dlist = []
    for y in k:
        if y != '\n':
            dlist.append(y)
        else:
            break
    return dlist

This is what i have tried.

回答1:

Using itertools.groupby would do the job (grouping by not being a linefeed):

import itertools

a = [1,2,3,4,5,'\n',6,7,8,9,0,'\n',3,45,6,7,2]

new_list = [list(x) for k,x in itertools.groupby(a,key=lambda x : x!='\n') if k]

print(new_list)

We compare the key truth value to filter out the occurrences of \n

result:

[[1, 2, 3, 4, 5], [6, 7, 8, 9, 0], [3, 45, 6, 7, 2]]

回答2:

example code:

lst = [[]]
for x in a:
    if x != '\n':
        lst[-1].append(x)
    else:
        lst.append([])
print(lst)

output:

[[1, 2, 3, 4, 5], [6, 7, 8, 9, 0], [3, 45, 6, 7, 2]]

回答3:

This is how I did it but there must be better solutions.

x = 0
output = [[]]
for item in a:
    if item != "\n":
        output[x].append(item)
    else:
        x += 1
        output.append([])

print(output)

回答4:

Here is the basic approach:

EDIT: Good heavens! Silly bug... here's a fix:

>>> sub = []
>>> final = []
>>> for e in a:
...     if e == '\n':
...         final.append(sub)
...         sub = []
...     else:
...         sub.append(e)
... else:
...     final.append(sub)
...
>>> final
[[1, 2, 3, 4, 5], [6, 7, 8, 9, 0], [3, 45, 6, 7, 2]]
>>>

There are other ways, but this is the naive imperative way.

来源：https://stackoverflow.com/questions/41880903/how-can-i-create-multidimensional-list-in-python