Flake8 will look at your code and check for style issues. It's automatable, which is great, but it's also very simple to use.

This is the `code.py`

file that we start with;

```
import pandas as pd
from numpy import *
settings = {"a": 1, "b": 2, "c": 3, "a": 2}
def fibonachi( s1, s2, n ):
"""
calculates the fibonachi sequence
with given custom numbers
"""
result = [s1 , s2]
for i in range( n ):
s1, s2 = s2, s1 + s2
result.append(s2)
return result
def fibonachi_standard(n):
"""
calculates the standard fibonachi sequence
"""
return Fibonachi(s1=1, s2=2, n)
```

We then run the following;

```
flake8 code.py
```

This gives us a list of errors and we remove them one by one.

```
settings = {"a": 1, "b": 2, "c": 3}
def fibonachi(s1, s2, n):
"""
calculates the fibonachi sequence
with given custom numbers
"""
result = [s1, s2]
for i in range(n):
s1, s2 = s2, s1 + s2
result.append(s2)
return result
def fibonachi_standard(n):
"""
calculates the standard fibonachi sequence
"""
return fibonachi(s1=1, s2=2, n)
```