> ## 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.

# Use File Iterator

#### Sourcery refactoring id: `use-file-iterator`

#### Description

Use the in-built file iterator rather than calling `readlines()`

#### Before

```python
with open("foo") as f:
    for line in f.readlines():
        print(line)
```

#### After

```python
with open("foo") as f:
    for line in f:
        print(line)
```

#### Explanation

The file object that Python returns when you open a file is a lazy iterator over
that file's lines. This means that there is no need to call `readlines` to
iterate over it. Iterating directly is shorter, and also does not load the whole
file into memory with a list object ( which `readlines` does) so can be more
performant.