---
# System prepended metadata

title: Typing library

---

 # Typing library
 
 ## `import typing`
 
 
This function allows you to do checks on the parameters/arguments that you pass into your functions in the function parameters of a function
 
 ### e.g. from lab09_deploy

 `def muliply_by_two(number : int):`
In this example, we can see 
* parameter 'number', this is the argument that is being passed in 
* the int is the specific type we want 'number to be'
* if 'number' is not of type int this function will not run

### e.g. from lab09_deploy
```
`def sum_iterable(numbers: (list, dict, tuple)):
```

You are able to have number be more than just one type
* the parameter 'numbers' here can be either a list, dict or tuple
* NB: iterable just means that you can loop through it