Checker pep257 has been renamed to pydocstyle.

References:
- https://github.com/PyCQA/pydocstyle/issues/172
- https://github.com/PyCQA/pydocstyle/pull/173

plugin/syntastic.vim

@@ -19,7 +19,7 @@ if has('reltime')
     lockvar! g:_SYNTASTIC_START
 endif
 
-let g:_SYNTASTIC_VERSION = '3.7.0-90'
+let g:_SYNTASTIC_VERSION = '3.7.0-91'
 lockvar g:_SYNTASTIC_VERSION
 
 " Sanity checks {{{1

syntax_checkers/python/pep257.vim

@@ -1,6 +1,13 @@
 "============================================================================
 "File:        pep257.vim
-"Description: Docstring style checking plugin for syntastic.vim
+"Description: Syntax checking plugin for syntastic
+"Maintainer:  LCD 47 <lcd047 at gmail dot com>
+"License:     This program is free software. It comes without any warranty,
+"             to the extent permitted by applicable law. You can redistribute
+"             it and/or modify it under the terms of the Do What The Fuck You
+"             Want To Public License, Version 2, as published by Sam Hocevar.
+"             See http://sam.zoy.org/wtfpl/COPYING for more details.
+"
 "============================================================================
 
 if exists('g:loaded_syntastic_python_pep257_checker')
@@ -8,52 +15,9 @@ if exists('g:loaded_syntastic_python_pep257_checker')
 endif
 let g:loaded_syntastic_python_pep257_checker = 1
 
-let s:save_cpo = &cpo
-set cpo&vim
-
-function! SyntaxCheckers_python_pep257_GetLocList() dict
-    if !exists('s:pep257_new')
-        let s:pep257_new = syntastic#util#versionIsAtLeast(self.getVersion(), [0, 3])
-    endif
-
-    let makeprg = self.makeprgBuild({})
-
-    if s:pep257_new
-        let errorformat =
-            \ '%E%f:%l %.%#:,' .
-            \ '%+C        %m'
-    else
-        let errorformat =
-            \ '%E%f:%l:%c%\%.%\%.%\d%\+:%\d%\+: %m,' .
-            \ '%E%f:%l:%c: %m,' .
-            \ '%+C    %m'
-    endif
-
-    let env = syntastic#util#isRunningWindows() ? {} : { 'TERM': 'dumb' }
-
-    let loclist = SyntasticMake({
-        \ 'makeprg': makeprg,
-        \ 'errorformat': errorformat,
-        \ 'env': env,
-        \ 'subtype': 'Style',
-        \ 'preprocess': 'killEmpty',
-        \ 'postprocess': ['compressWhitespace'] })
-
-    if s:pep257_new == 0
-        " byte offsets rather than column numbers
-        for e in loclist
-            let e['col'] = get(e, 'col', 0) + 1
-        endfor
-    endif
-
-    return loclist
-endfunction
-
 call g:SyntasticRegistry.CreateAndRegisterChecker({
     \ 'filetype': 'python',
-    \ 'name': 'pep257'})
-
-let &cpo = s:save_cpo
-unlet s:save_cpo
+    \ 'name': 'pep257',
+    \ 'redirect': 'python/pydocstyle'})
 
 " vim: set sw=4 sts=4 et fdm=marker:

syntax_checkers/python/pydocstyle.vim

@@ -0,0 +1,66 @@
+"============================================================================
+"File:        pydocstyle.vim
+"Description: Syntax checking plugin for syntastic
+"Maintainer:  LCD 47 <lcd047 at gmail dot com>
+"License:     This program is free software. It comes without any warranty,
+"             to the extent permitted by applicable law. You can redistribute
+"             it and/or modify it under the terms of the Do What The Fuck You
+"             Want To Public License, Version 2, as published by Sam Hocevar.
+"             See http://sam.zoy.org/wtfpl/COPYING for more details.
+"
+"============================================================================
+
+if exists('g:loaded_syntastic_python_pydocstyle_checker')
+    finish
+endif
+let g:loaded_syntastic_python_pydocstyle_checker = 1
+
+let s:save_cpo = &cpo
+set cpo&vim
+
+function! SyntaxCheckers_python_pydocstyle_GetLocList() dict
+    if !exists('s:pydocstyle_new')
+        let s:pydocstyle_new = syntastic#util#versionIsAtLeast(self.getVersion(), [0, 3])
+    endif
+
+    let makeprg = self.makeprgBuild({})
+
+    if s:pydocstyle_new
+        let errorformat =
+            \ '%E%f:%l %.%#:,' .
+            \ '%+C        %m'
+    else
+        let errorformat =
+            \ '%E%f:%l:%c%\%.%\%.%\d%\+:%\d%\+: %m,' .
+            \ '%E%f:%l:%c: %m,' .
+            \ '%+C    %m'
+    endif
+
+    let env = syntastic#util#isRunningWindows() ? {} : { 'TERM': 'dumb' }
+
+    let loclist = SyntasticMake({
+        \ 'makeprg': makeprg,
+        \ 'errorformat': errorformat,
+        \ 'env': env,
+        \ 'subtype': 'Style',
+        \ 'preprocess': 'killEmpty',
+        \ 'postprocess': ['compressWhitespace'] })
+
+    if s:pydocstyle_new == 0
+        " byte offsets rather than column numbers
+        for e in loclist
+            let e['col'] = get(e, 'col', 0) + 1
+        endfor
+    endif
+
+    return loclist
+endfunction
+
+call g:SyntasticRegistry.CreateAndRegisterChecker({
+    \ 'filetype': 'python',
+    \ 'name': 'pydocstyle'})
+
+let &cpo = s:save_cpo
+unlet s:save_cpo
+
+" vim: set sw=4 sts=4 et fdm=marker: