How small/large is the Drupal core codebase?

I wanted to know how many lines of code Drupal core has actually and I investigated it some days ago.

The returned numbers below mean lines of code respectively.

Drupal 7.51:

$ # Download Drupal
$ drush dl drupal-7.51

$ # Include all the .module, .inc and .php files.
$ find drupal-7.51 * | ag '\.(module|inc|php)$' | xargs cat | wc -l
  422884

$ # Include above files but exclude test-related ones.
$ find drupal-7.51 * | ag '\.(module|inc|php)$' | ag -v 'test' | xargs cat | wc -l
  330026

$ # Include all JS files.
$ find . * | ag '\.(js)$' | xargs cat | wc -l
  18554

$ # Include all JS files except for test-related ones.
$ find . * | ag '\.(js)$' | ag -v 'test' | xargs cat | wc -l
  18254

This is mere a simple calculation but is enough to grasp sizes roughly. If I ignore test-related files, there are 330 thousands lines of PHP code. That is, for example, If I read 1,000 lines a day, it takes almost 1 years. I see.

Of course, I was interested in the case of D8.

Drupal 8.2.2:

$ # Download Drupal
$ drush dl drupal-8.2.2

$ # Include all the php files. Following files are excluded.
$ # - Files in Compser packages
$ # - Test-related files
$ # - Transliteration-related files
$ # - (Of course, Twig template is not included because extension '.twig' is not specified.)
$ find drupal-8.2.2/core * | ag '\.(module|inc|php)$' | ag -v 'vendor' | ag -v 'test' | ag -v 'Transliteration' | xargs cat | wc -l
  917282

$ find core * | ag '\.(js)$' | ag -v 'vendor' | ag -v 'test' | ag -v 'Transliteration' | xargs cat | wc -l
  52874

Hmm. It seems that there're more than 900 thousands lines of code even without the vendor/ directory... It will take 900 days if I read 1,000 lines a day. Really? Surely Drupal 8 took a big jump from D7 but isn't it too large? (It's 3 times larger than D7.) I assume I missed something important to exclude from the count...

Anyway. I just wanted to know the rough volume and it's OK for now. Developers in 21st century (including me) are pretty lucky to see such a huge and sophisticated codebase for free :)

(FYI, if you are not used to ag command, ag is just a replacement of egrep.)