Python：两个嵌套循环

Question

I'm trying to find coding for Python version 3 doing these two things in basic coding (a loop nested inside another loop). I understand the basic premise of:

    for i in range(10)
        for j in range(10)

but I think it's the "i+___" math that's giving me trouble. I'm having trouble giving me these three types of outputs:

First:

    0
    0 1
    0 1 2
    0 1 2 3

Second:

    10
    11 12
    13 14 15
    16 17 18 19

Third:

    0 0 0 0 0 0 0 0 0
    1 1 1 1 1 1 1 1 1 
    2 2 2 2 2 2 2 2 2 

Any help would be greatly appreciated.

Answer 1

Third:

j=[]
for i in xrange(0,3):
     j.append([i]*9)

Answer 2

For python version 3.

First:

for i in range(4):
    for j in range(i+1):
        print(j, end="")
    print()

Second:

x=10
for i in range(1,5):
    for j in range(x,i+x):
        print(str(j)+" ", end="")
    x+=i
    print()

Third:

for i in range(3):
    print((str(i)+" ")*9)