Why is my setting of `set softtabstop` in vimrc being clobbered when editing python files?

Question

I am using vim 8.0.1763 on CentOS 8.1. Here is my ~/.vimrc

" Cool vim plugins : http://vimawesome.com/plugin/fugitive-vim
set number
filetype plugin on  " https://stackoverflow.com/questions/19754849/vim-syntax-highlighting-does-not-work
syntax on
" Stop annoying line wrapping when pasting
set paste
" Stop annoying line wrapping
set formatoptions-=tc
set ruler
set showmatch
set expandtab
set tabstop=4
set softtabstop=0

If I open a *.py file, and type :set softtabstop it returns 4. If I open another *.txt file, the same command returns 0. Clearly this is a python file specific behavior. The only place I can find this being set is in /usr/share/vim/vim80/ftplugin/python.vim

My intuition says that .vimrc should be loaded last.

Question

1. How do I get my settings in my .vimrc file to persist when opening *.py files?
2. What is the order of operation when loading vim configuration files?

Note :

This question was incorrectly marked as a duplicate question. The accepted answer of adding

augroup python
    autocmd!
    autocmd FileType python setlocal noet ts=4
augroup end

to my ~/.vimrc does not solve the Question 1 that I pose above. Also the previously previously asked question does not address my Question 2.

My question is unique in its own right. The accepted answer of my question is unique and not given in the previously asked question. My question should not be closed.

Answer 1

There is such a thing in vim called filetype plugin aka ftplugin. It is loaded for a filetype after it was read by vim thus overriding your .vimrc settings.

for a python check :e $VIMRUNTIME/ftplugin/python.vim (line 117):

if !exists("g:python_recommended_style") || g:python_recommended_style != 0
    " As suggested by PEP8.
    setlocal expandtab tabstop=4 softtabstop=4 shiftwidth=4
endif

You have at least 3 options here:

1. make the if statement false by setting let g:python_recommended_style == 0
2. override back settings in ~/.vim/after/ftplugin/python.vim -- create the file and add setlocal whatever there
3. override back settings in your vimrc using autocommands, for example:

augroup my_python_settings | au!
    au Filetype python setlocal softtabstop=1024
augroup END

You can check actual order of loaded scripts with :scriptnames.

In general see :h VIMINIT.