Is there an easy way to create dictionary like associative array in php? in php i can do:

```
> $x='a';
> while($x<d){
>     $arr[]['Letter']=$x;
>      $x++
>     }

```

The interpreter adds automatically a new number into empty brackets "[]"
so i can access letter `b` from `$arr[1]['Letter']`, etc.

Is there a way to do same with python?