# pandas-use-of-dot-iat (PD009)#

Derived from the **pandas-vet** linter.

## What it does#

Checks for uses of `.iat`

on Pandas objects.

## Why is this bad?#

The `.iat`

method selects a single value from a DataFrame or Series based
on an ordinal index, and is slightly faster than using `.iloc`

. However,
`.iloc`

is more idiomatic and versatile, as it can be used to select
multiple values at once.

If performance is an important consideration, convert the object to a NumPy
array, which will provide a much greater performance boost than using `.iat`

over `.iloc`

.

## Example#

Use instead:

Or, using NumPy:

```
import numpy as np
import pandas as pd
students_df = pd.read_csv("students.csv")
students_df.to_numpy()[0]
```