# Packing and Unpacking Arguments in Python Functions

##### 133 words — categories: python

You can pack and unpack functions arguments in Python.

If you have a function take takes in \(n\) arguments, you can’t just pass it a list of said arguments. Let’s say we have a linear function that takes in an array of \(x\)-values, a slope and intercept.

```
import numpy as np
x_array = np.linspace(1, 10, 10)
def linear(x, m, b):
return x * m + b
args = [2, 4]
```

```
# the operation below leads to
# TypeError: linear() missing 1 required positional argument: 'b'
linear(x_array, args)
```

Python takes in the `x_array`

and `args`

list as the first positional arguments. We can use the unpacking convention instead to break up `args`

into its constituents.

`linear(x_array, *args)`

`## array([ 6., 8., 10., 12., 14., 16., 18., 20., 22., 24.])`