Annoying Tab width

When using vim on termux, only in python file did vim use 4-space-width tab. And in other files(e.g. .html), a tab, a >> and a backspace are all 8 spaces.

And I tried to set the following in ~/.vimrc file. But it does not work.

set autoindent
set smartindent
set tabstop=4 " 统一缩进为4
set shiftwidth=4 "自动缩进长度
set expandtab " Tab转空格
set softtabstop=4

After Googling for a while, I found that it is said that there are some file specific settings which affects the setting in ~/.vimrc file.

Discussion on StackOverflow: https://stackoverflow.com/questions/14173766/vim-ignores-shiftwidth-specified-in-vimrc

And the struct of vim plugin: http://learnvimscriptthehardway.stevelosh.com/chapters/42.html#vimplugin

Then, I tried to write the config above to ~/.vim/after/settab.vim. And problem is still there.

Another saied use :verbose set tabstop? to see where did the variable last set.

And it showed it was in ~/.vim/view/xxxxx. That is because I run autocmd to save and load view. Then I deleted all files under it(the config still in ~/.vimrc). And I made mkview explicit by comment out the autocmd. Problem solved!