# Namedtuple Default Values

I've been making my way through a deep-dive python series on Udemy (I highly recommend it - [Python 3: Deep Dive by Dr. Fred Baptiste](https://www.udemy.com/course/python-3-deep-dive-part-1/). The course recently touched on the question of how to set default arguments on a `namedtuple`. I found out afterwards that as of python 3.7 `namedtuple` has a `defaults` argument ([see the docs](https://docs.python.org/3/library/collections.html#namedtuple-factory-function-for-tuples-with-named-fields)), making the following neat little trick largely irrelevant. We'll pretend that doesn't exist for the moment.

Dr. Baptiste's way around the problem relies on the `__new__` method and the `__defaults__` property, neither of which typically get much air time:

* `__new__` is a built in method on all classes. It creates an instance of the class (before `__init__` gets called)
    
* `__defaults__` is a property on all functions that stores the default values, and it's writable
    
    * if there are fewer defaults than function arguments, the values get "right aligned". See the screenshot:
        
        ![](https://cdn.hashnode.com/res/hashnode/image/upload/v1741464369706/1064ecb8-5d05-466e-a709-ca099e980220.png align="center")
        

If you're on python 3.7+, stick with the built-in option. If not though, good to know you can do this:

```python
from collections import namedtuple

Point = namedtuple("Point", ["x", "y", "z"])
Point.__new__.__defaults__ = (2, 3) # Default `y` to 2, and `z` to 3. `x` has no default

print(Point(1))
# Point(x=1, y=2, z=3)
```