set python tag files

vimfiles.stefan/after/ftplugin/python.vim

@@ -6,7 +6,20 @@ setlocal tabstop=4
 setlocal shiftwidth=4
 setlocal formatoptions=croq
 
-setlocal tags+=/usr/lib/python/tags
+function! Set_python_tag_files()
+python << endpython
+import vim
+import sys
+import os
+for p in sys.path:
+    tags = os.path.join(p, 'tags')
+    if os.path.exists(tags):
+        cmd = "setlocal tags+=%s" % tags
+        vim.command(cmd)
+endpython
+endfunction
+
+call Set_python_tag_files()
 nnoremap <TAB> :YcmCompleter GoTo<CR>
 " commenting
 let b:commentstring = '#'