How to insert elements in nested list?

Scripting
,
1 
for _ in range(2):

   a = [[1, 1, 1], [1, 1, 1], [0, 1, 1], [0, 0, 1]]
   b = [randint(0,1) for i in range(3)]
   c = [randint(0,1) for j in range(7)]
   a.append(b)
   a.insert(0,b)

   count = 0
   for i in a:
      i.insert(0,c[count])
      count += 1

the output is:

a = [
    [1, 0, 1, 1, 1],
    [0, 1, 1, 1],
    [1, 1, 1, 1],
    [1, 0, 1, 1],
    [1, 0, 0, 1],
    [1, 0, 1, 1, 1]
]

a = [
    [1, 0, 1, 1, 1],
    [0, 1, 1, 1],
    [1, 1, 1, 1],
    [1, 0, 1, 1],
    [1, 0, 0, 1],
    [1, 0, 1, 1, 1]
]

but I want first append and insert 2 list from b in list (a) then insert elements from c for each list in (a):

a = [
    [1, 0, 1, 1, 1],
    [0, 1, 1, 1, 1],
    [1, 1, 1, 1, 0],
    [1, 0, 1, 1, 1],
    [1, 0, 0, 1, 0],
    [1, 0, 1, 1, 1]
]

a = [
    [1, 0, 1, 1, 1],
    [0, 1, 1, 1, 1],
    [1, 1, 1, 1, 0],
    [1, 0, 1, 1, 1],
    [1, 0, 0, 1, 0],
    [1, 0, 1, 1, 1]
]
2

Hello,
is this it?

target_outer = 6
target_inner = 5
a = [[1, 1, 1], [1, 1, 1], [0, 1, 1], [0, 0, 1]]
while len(a) < target_outer:
    a.append([])
for l in a:
    while len(l) < target_inner:
        l.insert(0,randint(0,1))