Question: Seemingly conflicting descriptions given in authoritative documentation sources.

[A Standard for Robot Exclusion](https://www.robotstxt.org/orig.html):

('record' refers to each user-agent block)

> 
> "The file consists of one or more records separated by one or more
>  **blank** lines (terminated by CR,CR/NL, or NL). Each record contains
>  lines of the form ...".
> 
> 
> 

Google's [Robot.txt Specifications](https://developers.google.com/search/reference/robots_txt):

> 
> "... Note the **optional use** of white-space and **empty lines** to improve
>  readability."
> 
> 
> 

So -- *based on documentation that we have available to us* -- is this empty line here mandatory?

```
User-agent: *
Disallow: /this-directory/

User-agent: DotBot
Disallow: /this-directory/
Disallow: /and-this-directory/

```

Or, is this OK?

```
User-agent: *
Disallow: /this-directory/
User-agent: DotBot
Disallow: /this-directory/
Disallow: /and-this-directory/

```

Answer: 
If you look at the way Selenium imports the various flavours of `webdriver` to `selenium.webdriver` you can see that the import you want is [`Chrome`](https://github.com/SeleniumHQ/selenium/blob/selenium-4.0.0-alpha-3/py/selenium/webdriver/__init__.py#L21)

```
from .firefox.webdriver import WebDriver as Firefox  # noqa
from .chrome.webdriver import WebDriver as Chrome  # noqa

```

So you would do `driver = webdriver.Chrome()` or if you want Firefox, `webdriver.Firefox()`

By doing `webdriver.chrome()` you're importing & calling the actual `chrome` [module](https://github.com/SeleniumHQ/selenium/tree/selenium-4.0.0-alpha-3/py/selenium/webdriver/chrome)

In terms of your new error, you need to download the chromedriver executable and make sure it's in a folder which is available to python (included in your `PATH`). You can download chromedriver here; <https://sites.google.com/a/chromium.org/chromedriver/downloads>
The error in your title is different than the one in your post. 

```
TypeError: 'module' object is not callable

```

`chrome` should be capitalized in `webdriver.chrome()`:

```
driver = webdriver.Chrome() # .Chrome(), not .chrome()

```