Comprehensions can also be used to deal with nested iteration loops.

In python you might have a nested loop.

```
for i in range(5):
for j in range(i):
print((i, j))
```

This can also be turned into a comprehensions.

```
[(i, j) for i in range(5) for j in range(i)]
```

Even if there are if statements in the loops.

```
for i in range(5):
if i > 2:
for j in range(i):
if j < 2:
print((i, j))
```

You can still turn this into a comprehension.

```
[(i, j) for i in range(5) if i > 2 for j in range(i) if j < 2]
```