title: 6 Clean Tips to Improve Your Python Functions

Source: [this Indently video](https://www.youtube.com/watch?v=qvSjZ6AKfXQ).


## 1 Function return type
```py
def func() -> int:
    return 1
```
## 2 Function arg types
```py
def func(x: int) -> int
    return x + 1

def func(numbers: list[int]) -> list[int]
    numbers.<tab> # will autocomplete to list methods
    return numbers
```
## 3 star args 
```py
def sum_numbers(*numbers: float) -> float:
    # numbers is a tuple(float)
    return sum(numbers)
```
## 4 Keep code simple
* Every function has one job so as to make reuse easy

## 5 Documentation
```py
def f():
    "Explain what f does and how to use it"
```
## 6 Avoid globals
Sometimes globals are useful, but are messy as soon as you want to reuse code.
If code needs state to persist between function calls, factor things into a class.
One exception I have is a `should_quit` variable that other threads can pay attention to,
as a means to tell an arbitrary group of threads that they should quit at the earliest
opportunity.