VIM: tabs are replaced with spaces.

vim/vimrc

@@ -15,8 +15,10 @@ set viminfo='20,\"50	" read/write a .viminfo file, don't store more
 set history=50		" keep 50 lines of command line history
 set ruler		" show the cursor position all the time
 set tabstop=4		" make tabes to be equal to 4 space chars.
+set shiftwidth=4 	" for indentation shift by 4 chars.
 set expandtab		" this is for MG files.
-set shiftwidth=4 	" for shifting by 4 when pressing tab.
+set softtabstop=4	" insert/<BS> deletes 4 space chars.
+set smarttab        " insert/<BS> space in front of line instead of tab. 
 set fileformat=unix	" line ending is unix
 set textwidth=80	" 80 char text
 let g:netrw_preview = 1 " netrw open window to the right
@@ -56,8 +58,8 @@ if exists('&hidden')
 	set hidden
 endif
 
-" Instead of failing a command because of unsaved changes, instead raise a
-" dialogue asking if you wish to save changed files.
+" Instead of failing a command because of unsaved changes, raise a dialogue 
+" asking if you wish to save changed files.
 if exists('&confirm')
 	set confirm
 endif
@@ -87,9 +89,8 @@ if exists('&modeline')
 	set modeline
 	set modelines=10
 endif
-"
+
 "	Set fold method if supported
-"
 if has('folding')
 	set nofoldenable
 	set foldmethod=indent "fold based on indent
@@ -102,9 +103,18 @@ if has('folding')
 		autocmd FileType cpp setlocal foldmethod=syntax
 	endif
 endif
-"
+
+"	Unset expandtab for make files in any case.
+if has('autocmd')
+	autocmd FileType make setlocal noexpandtab
+endif
+
+"	Set expandtab for python files in any case.
+if has('autocmd')
+	autocmd FileType python setlocal expandtab
+endif
+
 "	P4
-"
 command! -nargs=* PFedit :!p4 edit <args> %
 command! -nargs=* PFrevert :!p4 revert <args> %
 command! -nargs=* PFdiff :!p4 diff <args> %