<p>List comprehensions can be useful in certain situations, but they can also be rather horrible to read.. As a slightly exaggerated example, how would you indent the following?</p>

<pre><code>allUuids = [x.id for x in self.db.query(schema.allPostsUuid).execute(timeout = 20) if x.type == "post" and x.deleted is not False]
</code></pre>

How about:
```
```
allUuids = [x.id for x in self.db.query(schema.allPostsUuid).execute(timeout = 20) 
                   if (x.type == "post" and x.deleted is not False)]
```
```
Generally, long lines can be avoided by pre-computing subexpressions into variables, which might add a minuscule performance cost:
```
```
query_ids = self.db.query(schema.allPostsUuid).execute(timeout = 20)
allUuids = [x.id for x in query_ids
                   if (x.type == "post" and x.deleted is not False)]
```
```
By the way, isn't '
```
is not False
```
' kind-of superfluous ? Are you worried about differentiating between None and False ? Because otherwise, it suffices to leave the condition as only: i
```
f (x.type == "post" and x.deleted)
```