L.append('что то там')

L[i][j]='как то так'

[0:n]

[1:n+1]

from collections import defaultdict
d = defaultdict(dict)
>>> d
defaultdict(<type 'dict'>, {})
>>> d[1][1] = 'your item'
>>> d
defaultdict(<type 'dict'>, {1: {1: 'your item'}})

class array(list):
    def __init__(self, length):
        self.extend([None] * length)
class matrix(list):
    def __init__(self, len_x, len_y):
        map(lambda row: self.append(array(len_x)), xrange(len_y))
a = matrix(12, 6)
a[2][10] = "sdfsdf"
print a

a = [1,2,3,4]
a.insert(0, None)
print a