# What does ** and * do for parameters in Python?

In Python, the **`*`** symbol is used to indicate that an argument can be passed to a function as a tuple. The **`**`** symbol is used to indicate that an argument can be passed to a function as a dictionary.

Here's an example of how you might use these symbols in a function definition:

```python
def my_function(arg1, *args, **kwargs):
    # arg1 is a required argument
    # args is a tuple of optional positional arguments
    # kwargs is a dictionary of optional keyword arguments
    pass
```

You can then call the function like this:

```python
my_function(1, 2, 3, 4, 5, keyword1=6, keyword2=7)
```

This would pass the following values to the function:

```python
arg1 = 1
args = (2, 3, 4, 5)
kwargs = {'keyword1': 6, 'keyword2': 7}
```

You can use the **`*`** and **`**`** syntax when calling a function as well. For example:

```python
def my_function(arg1, arg2):
    print(arg1)
    print(arg2)

my_list = [1, 2]
my_dict = {'arg2': 3}

my_function(*my_list, **my_dict)
```

This would output the following:

```python
1
3
```

The **`*`** and **`**`** symbols are used to unpack the values in the **`my_list`** and **`my_dict`** variables, respectively, and pass them as individual arguments to the **`my_function`** function.