Question: I have a .txt textfile with a list formatted like 
`[' ok ', ' test ', ' help ']`
How can I read/import this textfile list into a python list?

Answer: 
If you want to customize the css of the tooltip, then you can use `::ng-deep`. Add the following styles in your component's styles:

```css
::ng-deep .mat-tooltip {
    /* your own custom styles here */ 
    /* e.g. */
    color: yellow;
}

```

Another option is to set the [View Encapsulation](https://angular.io/guide/component-styles#view-encapsulation) to None in your component:

```js
@Component({ 
    templateUrl: './my.component.html', 
    styleUrls: ['./my.component.css'], 
    encapsulation: ViewEncapsulation.None
})

```

Then in your component css you dont have to use `::ng-deep`.

```css
.mat-tooltip {
    /* your own custom styles here */ 
    /* e.g. */
    color: yellow;
}

```
Always use the matTooltipClass and a custom class. Never use ::ng-deep directly on a material class and NEVER, NEVER set encapsulation: ViewEncapsulation.None. Angular components are made to be modular and have their own style. Both :ng-deep(or /deep/ or >>> or whatever they call it these days) and viewEncapsulation are going to override styles that you might want to keep contained in other components. I was fooled once by these, there is no easy work sometimes but these can cause you serious layout damage.