> ## 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.

# Dict-Literal

#### Sourcery rule id: `dict-literal`

#### Description

Replace `dict()` with `{}`


#### Before

```python
x = dict()
```

#### After

```python
x = {}
```



#### Explanation

The most concise and Pythonic way to create a dictionary is to use the `{}`
notation.

This fits in with the way we create dictionaries with items, saving a bit of
mental energy that might be taken up with thinking about two different ways of
creating dicts.

```python
x = {"first": "thing"}
```

Doing things this way has the added advantage of being a nice little performance
improvement.

Here are the timings before and after the change:

```
$ python3 -m timeit "x = dict()"
5000000 loops, best of 5: 69.8 nsec per loop
```

```
$ python3 -m timeit "x = {}"
20000000 loops, best of 5: 29.4 nsec per loop
```

Similar reasoning and performance results hold for replacing `list()` with `[]`.