Support custom python path

README.rst

@@ -57,3 +57,11 @@ You can also specify a particular Python version, so if `isort` is installed und
 .. code-block:: viml
 
     let g:vim_isort_python_version = 'python3'
+
+Or you can specify a full path to a Python executable (e.g., for a virtual environment):
+
+.. code-block:: viml
+
+    let g:vim_isort_python_version = '/home/user/.local/bin/python3'
+    " or
+    let g:vim_isort_python_version = '/home/user/myproject/.venv/bin/python'

ftplugin/python_vimisort.vim

@@ -1,5 +1,23 @@
+" Prevent multiple executions
+if exists('b:did_vim_isort_ftplugin')
+    finish
+endif
+let b:did_vim_isort_ftplugin = 1
+
+" Initialize config overrides if not already set
+if !exists('g:vim_isort_config_overrides')
+    let g:vim_isort_config_overrides = {}
+endif
+
+" Determine Python executable
 if exists('g:vim_isort_python_version')
-    if g:vim_isort_python_version ==? 'python2'
+    if g:vim_isort_python_version =~ '[/\\]'
+        if !executable(g:vim_isort_python_version)
+            throw 'Python executable not found at: ' . g:vim_isort_python_version
+        endif
+        let g:vim_isort_use_external_python = 1
+        let g:vim_isort_python_path = g:vim_isort_python_version
+    elseif g:vim_isort_python_version ==? 'python2'
         command! -nargs=1 AvailablePython python <args>
         let s:available_short_python = 'py'
     elseif g:vim_isort_python_version ==? 'python3'
@@ -14,21 +32,65 @@ else
         command! -nargs=1 AvailablePython python <args>
         let s:available_short_python = 'py'
     else
-        throw 'No python support present, vim-isort will be disabled'
+        throw 'No Python support present, vim-isort will be disabled'
     endif
 endif
 
-command! Isort exec("call vimisort#init()|AvailablePython isort_file()")
+" Define external isort function if needed
+if exists('g:vim_isort_use_external_python') && g:vim_isort_use_external_python
+    if !exists(':Isort')
+        command! Isort call s:IsortViaSystem()
+    endif
+
+    if !exists('*s:IsortViaSystem')
+        function! s:IsortViaSystem()
+            let l:file = expand('%:p')
+            if empty(l:file)
+                echoerr 'No file to sort'
+                return
+            endif
+
+            " Save view and write file
+            let l:view = winsaveview()
+            write
+
+            " Build config arguments
+            let l:config_args = ''
+            for [l:key, l:value] in items(g:vim_isort_config_overrides)
+                let l:config_args .= ' --' . substitute(l:key, '_', '-', 'g') . '=' . shellescape(l:value)
+            endfor
+
+            " Run isort
+            let l:cmd = shellescape(g:vim_isort_python_path) . ' -m isort ' . l:config_args . ' ' . shellescape(l:file)
+            let l:output = system(l:cmd)
 
+            if v:shell_error != 0
+                echoerr 'isort failed: ' . l:output
+            else
+                " Reload file and restore view safely
+                silent! edit!
+                call winrestview(l:view)
+            endif
+        endfunction
+    endif
+else
+    if !exists(':Isort')
+        command! Isort exec("call vimisort#init()|AvailablePython isort_file()")
+    endif
+endif
+
+" Default key mapping
 if !exists('g:vim_isort_map')
     let g:vim_isort_map = '<C-i>'
 endif
 
+" Apply key mappings
 if g:vim_isort_map != ''
-    " execute "vnoremap <buffer> " . g:vim_isort_map . " :call vimisort#init()<Cr>gv:" . s:available_short_python . " isort_visual()<CR>"
-    execute "vnoremap <buffer> " . g:vim_isort_map . " <Cmd>call vimisort#init()<Cr>:" . s:available_short_python . " isort_visual()<CR>"
-endif
-
-if !exists('g:vim_isort_config_overrides')
-    let g:vim_isort_config_overrides = {}
+    if exists('g:vim_isort_use_external_python') && g:vim_isort_use_external_python
+        execute "nnoremap <buffer> " . g:vim_isort_map . " :Isort<CR>"
+        execute "vnoremap <buffer> " . g:vim_isort_map . " :Isort<CR>"
+    else
+        execute "nnoremap <buffer> " . g:vim_isort_map . " <Cmd>call vimisort#init()<CR>:" . s:available_short_python . " isort_file()<CR>"
+        execute "vnoremap <buffer> " . g:vim_isort_map . " <Cmd>call vimisort#init()<CR>:" . s:available_short_python . " isort_visual()<CR>"
+    endif
 endif