My .vimrc configuration for working in Python with vim

.vimrc

" plugins
let need_to_install_plugins = 0
if empty(glob('~/.vim/autoload/plug.vim'))
    silent !curl -fLo ~/.vim/autoload/plug.vim --create-dirs
        \ https://raw.githubusercontent.com/junegunn/vim-plug/master/plug.vim
    "autocmd VimEnter * PlugInstall --sync | source $MYVIMRC
    let need_to_install_plugins = 1
endif

call plug#begin()
Plug 'tpope/vim-sensible'
Plug 'itchyny/lightline.vim'
Plug 'joshdick/onedark.vim'
Plug 'ap/vim-buftabline'
Plug 'airblade/vim-gitgutter'
Plug 'vim-scripts/The-NERD-tree'
Plug 'jistr/vim-nerdtree-tabs'
Plug 'Xuyuanp/nerdtree-git-plugin'
Plug 'scrooloose/syntastic'
Plug 'majutsushi/tagbar'
Plug 'vim-scripts/indentpython.vim'
Plug 'lepture/vim-jinja'
Plug 'pangloss/vim-javascript'
call plug#end()

filetype plugin indent on
syntax on

if need_to_install_plugins == 1
    echo "Installing plugins..."
    silent! PlugInstall
    echo "Done!"
    q
endif

" always show the status bar
set laststatus=2

" enable 256 colors
set t_Co=256
set t_ut=

" turn on line numbering
set number

" sane text files
set fileformat=unix
set encoding=utf-8
set fileencoding=utf-8

" sane editing
set tabstop=4
set shiftwidth=4
set softtabstop=4
set colorcolumn=80
set expandtab
set viminfo='25,\"50,n~/.viminfo

" word movement
imap <S-Left> <Esc>bi
nmap <S-Left> b
imap <S-Right> <Esc><Right>wi
nmap <S-Right> w

" indent/unindent with tab/shift-tab
nmap <Tab> >>
imap <S-Tab> <Esc><<i
nmap <S-tab> <<

" mouse
set mouse=a
let g:is_mouse_enabled = 1
noremap <silent> <Leader>m :call ToggleMouse()<CR>
function ToggleMouse()
    if g:is_mouse_enabled == 1
        echo "Mouse OFF"
        set mouse=
        let g:is_mouse_enabled = 0
    else
        echo "Mouse ON"
        set mouse=a
        let g:is_mouse_enabled = 1
    endif
endfunction

" color scheme
syntax on
colorscheme onedark
filetype on
filetype plugin indent on

" lightline
set noshowmode
let g:lightline = { 'colorscheme': 'onedark' }

" code folding
set foldmethod=indent
set foldlevel=99

" wrap toggle
setlocal nowrap
noremap <silent> <Leader>w :call ToggleWrap()<CR>
function ToggleWrap()
    if &wrap
        echo "Wrap OFF"
        setlocal nowrap
        set virtualedit=all
        silent! nunmap <buffer> <Up>
        silent! nunmap <buffer> <Down>
        silent! nunmap <buffer> <Home>
        silent! nunmap <buffer> <End>
        silent! iunmap <buffer> <Up>
        silent! iunmap <buffer> <Down>
        silent! iunmap <buffer> <Home>
        silent! iunmap <buffer> <End>
    else
        echo "Wrap ON"
        setlocal wrap linebreak nolist
        set virtualedit=
        setlocal display+=lastline
        noremap  <buffer> <silent> <Up>   gk
        noremap  <buffer> <silent> <Down> gj
        noremap  <buffer> <silent> <Home> g<Home>
        noremap  <buffer> <silent> <End>  g<End>
        inoremap <buffer> <silent> <Up>   <C-o>gk
        inoremap <buffer> <silent> <Down> <C-o>gj
        inoremap <buffer> <silent> <Home> <C-o>g<Home>
        inoremap <buffer> <silent> <End>  <C-o>g<End>
    endif
endfunction

" move through split windows
nmap <leader><Up> :wincmd k<CR>
nmap <leader><Down> :wincmd j<CR>
nmap <leader><Left> :wincmd h<CR>
nmap <leader><Right> :wincmd l<CR>

" move through buffers
nmap <leader>[ :bp!<CR>
nmap <leader>] :bn!<CR>
nmap <leader>x :bd<CR>

" restore place in file from previous session
autocmd BufReadPost * if line("'\"") > 1 && line("'\"") <= line("$") | exe "normal! g'\"" | endif

" file browser
let NERDTreeIgnore = ['\.pyc$', '__pycache__']
let NERDTreeMinimalUI = 1
let g:nerdtree_open = 0
map <leader>n :call NERDTreeToggle()<CR>
function NERDTreeToggle()
    NERDTreeTabsToggle
    if g:nerdtree_open == 1
        let g:nerdtree_open = 0
    else
        let g:nerdtree_open = 1
        wincmd p
    endif
endfunction

" syntastic
let g:syntastic_always_populate_loc_list = 1
let g:syntastic_auto_loc_list = 1
let g:syntastic_check_on_open = 0
let g:syntastic_check_on_wq = 0
map <leader>s :SyntasticCheck<CR>
map <leader>d :SyntasticReset<CR>
map <leader>e :lnext<CR>
map <leader>r :lprev<CR>

" tag list
map <leader>t :TagbarToggle<CR>

" copy, cut and paste
vmap <C-c> "+y
vmap <C-x> "+c
vmap <C-v> c<ESC>"+p
imap <C-v> <ESC>"+pa

" disable autoindent when pasting text
" source: https://coderwall.com/p/if9mda/automatically-set-paste-mode-in-vim-when-pasting-in-insert-mode
let &t_SI .= "\<Esc>[?2004h"
let &t_EI .= "\<Esc>[?2004l"

function! XTermPasteBegin()
    set pastetoggle=<Esc>[201~
    set paste
    return ""
endfunction

inoremap <special> <expr> <Esc>[200~ XTermPasteBegin()