lint: Add support for cython-lint

.coveragerc

@@ -14,4 +14,4 @@ source =
 [report]
 exclude_lines =
   .*#\s*(pragma)[:\s]?\s*(no)\s*(cover)
-  .*#~>\s*
+  .*#\s*~>\s*

.cython-lint.toml

@@ -0,0 +1,9 @@
+[tool.cython-lint]
+exclude = "libmpi\\.pxd"
+ignore = [
+    "E201",  # whitespace after '('
+    "E202",  # whitespace before ')'
+    "E221",  # multiple spaces before operator
+    "E222",  # multiple spaces after operator
+    "E701",  # multiple statements on one line (colon)
+]

.github/workflows/ci-check.yml

@@ -116,6 +116,9 @@ jobs:
     - name: cython
       run:  conf/cythonize.sh -Wextra -Werror
 
+    - name: cython-lint
+      run:  cython-lint .
+
     - name: yamllint
       run:  yamllint .
 

conf/cythonize.sh

@@ -1,4 +1,5 @@
 #!/bin/sh
+set -eu
 topdir=$(cd $(dirname "$0")/.. && pwd)
 python "$topdir/conf/cythonize.py" \
     --working "$topdir" $@ \

conf/requirements-lint.txt

@@ -1,5 +1,6 @@
 codespell
 cython
+cython-lint
 flake8
 flake8-assertive
 flake8-bandit

demo/cython/helloworld.pyx

@@ -2,7 +2,6 @@ cdef extern from "mpi-compat.h": pass
 
 # ---------
 
-
 # Python-level module import
 # (file: mpi4py/MPI.so)
 
@@ -17,11 +16,8 @@ pname = MPI.Get_processor_name()
 hwmess = "Hello, World! I am process %d of %d on %s."
 print (hwmess % (rank, size, pname))
 
-
-
 # ---------
 
-
 # Cython-level cimport
 # this make available mpi4py's Python extension types
 # (file:  mpi4py/include/mpi4py/MPI.pxd)
@@ -34,10 +30,8 @@ from mpi4py.MPI cimport Intracomm as IntracommType
 cdef MPI.Comm WORLD = MPI.COMM_WORLD
 cdef IntracommType SELF = MPI.COMM_SELF
 
-
 # ---------
 
-
 # Cython-level cimport with PXD file
 # this make available the native MPI C API
 # with namespace-protection (stuff accessed as mpi.XXX)
@@ -58,10 +52,9 @@ ierr1 = mpi.MPI_Comm_rank(mpi.MPI_COMM_WORLD, &rank1)
 cdef int rlen1=0
 cdef char pname1[mpi.MPI_MAX_PROCESSOR_NAME]
 ierr1 = mpi.MPI_Get_processor_name(pname1, &rlen1)
-pname1[rlen1] = 0 # just in case ;-)
+pname1[rlen1] = 0  # just in case ;-)
 
 hwmess = "Hello, World! I am process %d of %d on %s."
 print (hwmess % (rank1, size1, pname1))
 
-
 # ---------

demo/wrap-cython/helloworld.pyx

@@ -1,10 +1,11 @@
-cdef extern from "mpi-compat.h": pass
+cdef extern from "mpi-compat.h":
+    pass
+cdef extern from "stdio.h":
+    int printf(char*, ...)
 
 cimport mpi4py.MPI as MPI
 from mpi4py.libmpi cimport *
 
-cdef extern from "stdio.h":
-    int printf(char*, ...)
 
 cdef void c_sayhello(MPI_Comm comm):
     cdef int size, rank, plen
@@ -18,6 +19,7 @@ cdef void c_sayhello(MPI_Comm comm):
     printf(b"Hello, World! I am process %d of %d on %s.\n",
            rank, size, pname)
 
+
 def sayhello(MPI.Comm comm not None ):
     cdef MPI_Comm c_comm = comm.ob_mpi
     c_sayhello(c_comm)

src/mpi4py/MPI.pxd

@@ -29,23 +29,23 @@ cdef extern from *:
 ctypedef public api class Datatype [
     type   PyMPIDatatype_Type,
     object PyMPIDatatypeObject,
-    ]:
+]:
     cdef MPI_Datatype ob_mpi
     cdef unsigned     flags
     cdef object     __weakref__
 
 ctypedef public api class Status [
     type   PyMPIStatus_Type,
     object PyMPIStatusObject,
-    ]:
+]:
     cdef MPI_Status ob_mpi
     cdef unsigned   flags
     cdef object   __weakref__
 
 ctypedef public api class Request [
     type   PyMPIRequest_Type,
     object PyMPIRequestObject,
-    ]:
+]:
     cdef MPI_Request ob_mpi
     cdef unsigned    flags
     cdef object    __weakref__
@@ -54,19 +54,19 @@ ctypedef public api class Request [
 ctypedef public api class Prequest(Request) [
     type   PyMPIPrequest_Type,
     object PyMPIPrequestObject,
-    ]:
+]:
     pass
 
 ctypedef public api class Grequest(Request) [
     type   PyMPIGrequest_Type,
     object PyMPIGrequestObject,
-    ]:
+]:
     cdef MPI_Request ob_grequest
 
 ctypedef public api class Message [
     type   PyMPIMessage_Type,
     object PyMPIMessageObject,
-    ]:
+]:
     cdef MPI_Message ob_mpi
     cdef unsigned    flags
     cdef object    __weakref__
@@ -75,7 +75,7 @@ ctypedef public api class Message [
 ctypedef public api class Op [
     type   PyMPIOp_Type,
     object PyMPIOpObject,
-    ]:
+]:
     cdef MPI_Op   ob_mpi
     cdef unsigned flags
     cdef object __weakref__
@@ -84,83 +84,83 @@ ctypedef public api class Op [
 ctypedef public api class Group [
     type   PyMPIGroup_Type,
     object PyMPIGroupObject,
-    ]:
+]:
     cdef MPI_Group ob_mpi
     cdef unsigned  flags
     cdef object  __weakref__
 
 ctypedef public api class Info [
     type   PyMPIInfo_Type,
     object PyMPIInfoObject,
-    ]:
+]:
     cdef MPI_Info ob_mpi
     cdef unsigned flags
     cdef object __weakref__
 
 ctypedef public api class Errhandler [
     type   PyMPIErrhandler_Type,
     object PyMPIErrhandlerObject,
-    ]:
+]:
     cdef MPI_Errhandler ob_mpi
     cdef unsigned       flags
     cdef object       __weakref__
 
 ctypedef public api class Session [
     type   PyMPISession_Type,
     object PyMPISessionObject,
-    ]:
+]:
     cdef MPI_Session ob_mpi
     cdef unsigned    flags
     cdef object     __weakref__
 
 ctypedef public api class Comm [
     type   PyMPIComm_Type,
     object PyMPICommObject,
-    ]:
+]:
     cdef MPI_Comm ob_mpi
     cdef unsigned flags
     cdef object __weakref__
 
 ctypedef public api class Intracomm(Comm) [
     type   PyMPIIntracomm_Type,
     object PyMPIIntracommObject,
-    ]:
+]:
     pass
 
 ctypedef public api class Topocomm(Intracomm) [
     type   PyMPITopocomm_Type,
     object PyMPITopocommObject,
-    ]:
+]:
     pass
 
 ctypedef public api class Cartcomm(Topocomm) [
     type   PyMPICartcomm_Type,
     object PyMPICartcommObject,
-    ]:
+]:
     pass
 
 ctypedef public api class Graphcomm(Topocomm) [
     type   PyMPIGraphcomm_Type,
     object PyMPIGraphcommObject,
-    ]:
+]:
     pass
 
 ctypedef public api class Distgraphcomm(Topocomm) [
     type   PyMPIDistgraphcomm_Type,
     object PyMPIDistgraphcommObject,
-    ]:
+]:
     pass
 
 ctypedef public api class Intercomm(Comm) [
     type   PyMPIIntercomm_Type,
     object PyMPIIntercommObject,
-    ]:
+]:
     pass
 
 ctypedef public api class Win [
     type   PyMPIWin_Type,
     object PyMPIWinObject,
-    ]:
+]:
     cdef MPI_Win  ob_mpi
     cdef unsigned flags
     cdef object __weakref__
@@ -169,7 +169,7 @@ ctypedef public api class Win [
 ctypedef public api class File [
     type   PyMPIFile_Type,
     object PyMPIFileObject,
-    ]:
+]:
     cdef MPI_File ob_mpi
     cdef unsigned flags
     cdef object __weakref__

src/mpi4py/MPI.pyx

@@ -1,15 +1,15 @@
-#cython: language_level=3str
-#cython: embedsignature=True
-#cython: embedsignature.format=python
-#cython: annotation_typing=False
-#cython: cdivision=True
-#cython: auto_pickle=False
-#cython: always_allow_keywords=True
-#cython: allow_none_for_extension_args=False
-#cython: autotestdict=False
-#cython: warn.multiple_declarators=False
-#cython: optimize.use_switch=False
-#cython: binding=True
+# cython: language_level=3str
+# cython: embedsignature=True
+# cython: embedsignature.format=python
+# cython: annotation_typing=False
+# cython: cdivision=True
+# cython: auto_pickle=False
+# cython: always_allow_keywords=True
+# cython: allow_none_for_extension_args=False
+# cython: autotestdict=False
+# cython: warn.multiple_declarators=False
+# cython: optimize.use_switch=False
+# cython: binding=True
 
 from __future__ import annotations
 cimport cython  # no-cython-lint

src/mpi4py/MPI/CAPI.pxi

@@ -17,9 +17,11 @@ cdef api MPI_Datatype* PyMPIDatatype_Get(object arg) except NULL:
 
 cdef api object PyMPIStatus_New(MPI_Status *arg):
     cdef Status obj = Status.__new__(Status)
-    if (arg != NULL and
+    if (
+        arg != NULL and
         arg != MPI_STATUS_IGNORE and
-        arg != MPI_STATUSES_IGNORE):
+        arg != MPI_STATUSES_IGNORE
+    ):
         obj.ob_mpi = arg[0]
     return obj