> ## Documentation Index
> Fetch the complete documentation index at: https://docs.sourcery.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Del Comprehension

#### Sourcery refactoring id: `del-comprehension`

#### Description:

Replaces cases where deletions are made via `for` loops with comprehensions

#### Before:

```python
x1 = {"a": 1, "b": 2, "c": 3}
for key in x1.copy():  # can't iterate over a variable that changes size
    if key not in x0:
        del x1[key]
```

#### After:

```python
x1 = {"a": 1, "b": 2, "c": 3}
x1 = {key: value for key, value in x1.items() if key in x0}
```

#### Explanation:

When creating a filtered list in Python it is shorter and more readable to use a
comprehension than to copy a list and delete the unneeded keys.