# Python Code Example: double nested for-loop

This code defines a nested loop structure with three levels: an outer loop, a middle loop, and an inner loop.

The outer loop (`for i in range(3, 5)`) will run twice, with `i` taking on the values `3` and `4`.

For each iteration of the outer loop, the middle loop (`for j in range(1, 10)`) will run 9 times, with `j` taking on the values `1` through `9`.

For each iteration of the middle loop, the inner loop (`for k in range(1, 5)`) will run 4 times, with `k` taking on the values `1` through `4`.

At each iteration of the inner loop, the code will print the product of `i`, `j`, and `k` (separated by a space), using `print(i * j * k, end=" ")`. After each iteration of the inner loop, a newline character (`\n`) is printed to create a blank line (`print()`).

After each iteration of the middle loop, another newline character is printed, creating a blank line (`print()`). This separates the products of each iteration of the middle loop.

After each iteration of the outer loop, another newline character is printed, creating a blank line. This separates the products of each iteration of the outer loop.

So, the code will print a series of products, separated by spaces, with blank lines separating the products of each iteration of the middle loop and the outer loop.

``````for i in range(3, 5):
for j in range(1, 10):
for k in range(1, 5):
print(i * j * k, end=" ")
print()
print()``````
##### Output
``````3 6 9 12
6 12 18 24
9 18 27 36
12 24 36 48
15 30 45 60
18 36 54 72
21 42 63 84
24 48 72 96
27 54 81 108

4 8 12 16
8 16 24 32
12 24 36 48
16 32 48 64
20 40 60 80
24 48 72 96
28 56 84 112
32 64 96 128
36 72 108 144 ``````