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;
}

```
Angular Material tooltip exposes input property 'matTooltipClass'

So in the HTML

```
 ` 

        <mat-icon color="primary" matTooltip="test"
                    [matTooltipClass]="{ 'tool-tip': true }"
                    >help</mat-icon>

    `

```

In the CSS

```
   .tool-tip {
      color: white;
      background-color: red;

    }

```