diff --git a/app/pe/pe_tools.py b/app/pe/pe_tools.py
index aef08398..46e706ee 100644
--- a/app/pe/pe_tools.py
+++ b/app/pe/pe_tools.py
@@ -44,7 +44,6 @@ import unicodedata
 
 import app.scodoc.sco_utils as scu
 from app import log
-import six
 
 PE_DEBUG = 0
 
@@ -145,7 +144,7 @@ def escape_for_latex(s):
     }
     exp = re.compile(
         "|".join(
-            re.escape(six.text_type(key))
+            re.escape(key)
             for key in sorted(list(conv.keys()), key=lambda item: -len(item))
         )
     )
diff --git a/app/scodoc/gen_tables.py b/app/scodoc/gen_tables.py
index f6ac6c34..a986494e 100644
--- a/app/scodoc/gen_tables.py
+++ b/app/scodoc/gen_tables.py
@@ -752,6 +752,8 @@ if __name__ == "__main__":
     )
     document.build(objects)
     data = doc.getvalue()
-    open("/tmp/gen_table.pdf", "wb").write(data)
+    with open("/tmp/gen_table.pdf", "wb") as f:
+        f.write(data)
     p = T.make_page(format="pdf")
-    open("toto.pdf", "wb").write(p)
+    with open("toto.pdf", "wb") as f:
+        f.write(p)
diff --git a/app/scodoc/intervals.py b/app/scodoc/intervals.py
index 9c9b59cc..f4159bea 100644
--- a/app/scodoc/intervals.py
+++ b/app/scodoc/intervals.py
@@ -4,11 +4,8 @@
 
 # Code from http://code.activestate.com/recipes/457411/
 
-from __future__ import print_function
 from bisect import bisect_left, bisect_right
 
-from six.moves import zip
-
 
 class intervalmap(object):
     """
diff --git a/app/scodoc/notes_table.py b/app/scodoc/notes_table.py
index 3ded5868..a06c2ccd 100644
--- a/app/scodoc/notes_table.py
+++ b/app/scodoc/notes_table.py
@@ -27,10 +27,7 @@
 
 """Calculs sur les notes et cache des resultats
 """
-import inspect
-import os
-import pdb
-import time
+
 from operator import itemgetter
 
 from flask import g, url_for
@@ -40,12 +37,8 @@ import app.scodoc.sco_utils as scu
 import app.scodoc.notesdb as ndb
 from app import log
 from app.scodoc.sco_formulas import NoteVector
-from app.scodoc.sco_exceptions import (
-    AccessDenied,
-    NoteProcessError,
-    ScoException,
-    ScoValueError,
-)
+from app.scodoc.sco_exceptions import ScoValueError
+
 from app.scodoc.sco_formsemestre import (
     formsemestre_uecoef_list,
     formsemestre_uecoef_create,
diff --git a/app/scodoc/sco_archives.py b/app/scodoc/sco_archives.py
index 8ebab00a..f747d912 100644
--- a/app/scodoc/sco_archives.py
+++ b/app/scodoc/sco_archives.py
@@ -203,7 +203,9 @@ class BaseArchiver(object):
     def get_archive_description(self, archive_id):
         """Return description of archive"""
         self.initialize()
-        return open(os.path.join(archive_id, "_description.txt")).read()
+        with open(os.path.join(archive_id, "_description.txt")) as f:
+            descr = f.read()
+        return descr
 
     def create_obj_archive(self, oid: int, description: str):
         """Creates a new archive for this object and returns its id."""
@@ -232,9 +234,8 @@ class BaseArchiver(object):
         try:
             scu.GSL.acquire()
             fname = os.path.join(archive_id, filename)
-            f = open(fname, "wb")
-            f.write(data)
-            f.close()
+            with open(fname, "wb") as f:
+                f.write(data)
         finally:
             scu.GSL.release()
         return filename
@@ -247,7 +248,9 @@ class BaseArchiver(object):
             raise ValueError("invalid filename")
         fname = os.path.join(archive_id, filename)
         log("reading archive file %s" % fname)
-        return open(fname, "rb").read()
+        with open(fname, "rb") as f:
+            data = f.read()
+        return data
 
     def get_archived_file(self, oid, archive_name, filename):
         """Recupere donnees du fichier indiqué et envoie au client"""
diff --git a/app/scodoc/sco_codes_parcours.py b/app/scodoc/sco_codes_parcours.py
index 251a7ada..ce0ab664 100644
--- a/app/scodoc/sco_codes_parcours.py
+++ b/app/scodoc/sco_codes_parcours.py
@@ -28,7 +28,6 @@
 """Semestres: Codes gestion parcours (constantes)
 """
 import collections
-from six.moves import range
 
 NOTES_TOLERANCE = 0.00499999999999  # si note >= (BARRE-TOLERANCE), considere ok
 # (permet d'eviter d'afficher 10.00 sous barre alors que la moyenne vaut 9.999)
diff --git a/app/scodoc/sco_dump_db.py b/app/scodoc/sco_dump_db.py
index 126d2783..8fa2e209 100644
--- a/app/scodoc/sco_dump_db.py
+++ b/app/scodoc/sco_dump_db.py
@@ -167,7 +167,8 @@ def _anonymize_db(ano_db_name):
 
 def _get_scodoc_serial():
     try:
-        return int(open(os.path.join(scu.SCODOC_VERSION_DIR, "scodoc.sn")).read())
+        with open(os.path.join(scu.SCODOC_VERSION_DIR, "scodoc.sn")) as f:
+            return int(f.read())
     except:
         return 0
 
diff --git a/app/scodoc/sco_edt_cal.py b/app/scodoc/sco_edt_cal.py
index 312a6a4f..f526c092 100644
--- a/app/scodoc/sco_edt_cal.py
+++ b/app/scodoc/sco_edt_cal.py
@@ -33,10 +33,10 @@ XXX incompatible avec les ics HyperPlanning Paris 13 (était pour GPU).
 
 """
 
-import six.moves.urllib.request, six.moves.urllib.error, six.moves.urllib.parse
-import traceback
 import icalendar
 import pprint
+import traceback
+import urllib
 
 import app.scodoc.sco_utils as scu
 from app import log
@@ -80,7 +80,7 @@ def formsemestre_load_ics(sem):
         ics_data = ""
     else:
         log("Loading edt from %s" % ics_url)
-        f = six.moves.urllib.request.urlopen(
+        f = urllib.request.urlopen(
             ics_url, timeout=5
         )  # 5s TODO: add config parameter, eg for slow networks
         ics_data = f.read()
diff --git a/app/scodoc/sco_etud.py b/app/scodoc/sco_etud.py
index 53d68f96..a2f2aebc 100644
--- a/app/scodoc/sco_etud.py
+++ b/app/scodoc/sco_etud.py
@@ -830,8 +830,8 @@ appreciations_edit = _appreciationsEditor.edit
 def read_etablissements():
     filename = os.path.join(scu.SCO_TOOLS_DIR, scu.CONFIG.ETABL_FILENAME)
     log("reading %s" % filename)
-    f = open(filename)
-    L = [x[:-1].split(";") for x in f]
+    with open(filename) as f:
+        L = [x[:-1].split(";") for x in f]
     E = {}
     for l in L[1:]:
         E[l[0]] = {
diff --git a/app/scodoc/sco_formsemestre_edit.py b/app/scodoc/sco_formsemestre_edit.py
index 2e238fe5..e66ca28d 100644
--- a/app/scodoc/sco_formsemestre_edit.py
+++ b/app/scodoc/sco_formsemestre_edit.py
@@ -58,7 +58,6 @@ from app.scodoc import sco_permissions_check
 from app.scodoc import sco_portal_apogee
 from app.scodoc import sco_preferences
 from app.scodoc import sco_users
-import six
 
 
 def _default_sem_title(F):
diff --git a/app/scodoc/sco_formsemestre_validation.py b/app/scodoc/sco_formsemestre_validation.py
index 7c49c792..5319ee2a 100644
--- a/app/scodoc/sco_formsemestre_validation.py
+++ b/app/scodoc/sco_formsemestre_validation.py
@@ -27,7 +27,7 @@
 
 """Semestres: validation semestre et UE dans parcours
 """
-import six.moves.urllib.request, six.moves.urllib.parse, six.moves.urllib.error, time, datetime
+import time
 
 import flask
 from flask import url_for, g, request
@@ -494,7 +494,7 @@ def formsemestre_recap_parcours_table(
     with_links=False,
     with_all_columns=True,
     a_url="",
-    sem_info={},
+    sem_info=None,
     show_details=False,
 ):
     """Tableau HTML recap parcours
@@ -502,6 +502,7 @@ def formsemestre_recap_parcours_table(
     sem_info = { formsemestre_id : txt } permet d'ajouter des informations associées à chaque semestre
     with_all_columns: si faux, pas de colonne "assiduité".
     """
+    sem_info = sem_info or {}
     H = []
     linktmpl = '<span onclick="toggle_vis(this);" class="toggle_sem sem_%%s">%s</span>'
     minuslink = linktmpl % scu.icontag("minus_img", border="0", alt="-")
diff --git a/app/scodoc/sco_groups.py b/app/scodoc/sco_groups.py
index 0a776813..dac98924 100644
--- a/app/scodoc/sco_groups.py
+++ b/app/scodoc/sco_groups.py
@@ -59,8 +59,6 @@ from app.scodoc.sco_exceptions import ScoException, AccessDenied, ScoValueError
 from app.scodoc.sco_permissions import Permission
 from app.scodoc.TrivialFormulator import TrivialFormulator
 
-import six
-
 
 def checkGroupName(
     groupName,
@@ -732,10 +730,6 @@ def setGroups(
         group_name = fs[0].strip()
         if not group_name:
             continue
-        # ajax arguments are encoded in utf-8:
-        # group_name = six.text_type(group_name, "utf-8").encode(
-        #    scu.SCO_ENCODING
-        # )  # #py3 #sco8
         group_id = createGroup(partition_id, group_name)
         # Place dans ce groupe les etudiants indiqués:
         for etudid in fs[1:-1]:
diff --git a/app/scodoc/sco_pdf.py b/app/scodoc/sco_pdf.py
index c504ae17..77e6f4e1 100755
--- a/app/scodoc/sco_pdf.py
+++ b/app/scodoc/sco_pdf.py
@@ -350,7 +350,6 @@ def pdf_basic_page(
 
 
 # Gestion du lock pdf
-import threading, time, six.moves.queue, six.moves._thread
 
 
 class PDFLock(object):
diff --git a/app/scodoc/sco_portal_apogee.py b/app/scodoc/sco_portal_apogee.py
index e79b3531..07006aff 100644
--- a/app/scodoc/sco_portal_apogee.py
+++ b/app/scodoc/sco_portal_apogee.py
@@ -39,7 +39,6 @@ import app.scodoc.sco_utils as scu
 from app import log
 from app.scodoc.sco_exceptions import ScoValueError
 from app.scodoc import sco_preferences
-import six
 
 SCO_CACHE_ETAPE_FILENAME = os.path.join(scu.SCO_TMP_DIR, "last_etapes.xml")
 
@@ -386,7 +385,8 @@ def get_etapes_apogee():
             # cache le resultat (utile si le portail repond de façon intermitente)
             if infos:
                 log("get_etapes_apogee: caching result")
-                open(SCO_CACHE_ETAPE_FILENAME, "w").write(doc)
+                with open(SCO_CACHE_ETAPE_FILENAME, "w") as f:
+                    f.write(doc)
         except:
             log("invalid XML response from getEtapes Web Service\n%s" % etapes_url)
             # Avons nous la copie d'une réponse récente ?
diff --git a/app/scodoc/sco_report.py b/app/scodoc/sco_report.py
index 7d9a8082..078da669 100644
--- a/app/scodoc/sco_report.py
+++ b/app/scodoc/sco_report.py
@@ -31,7 +31,6 @@
 """
 import os
 import tempfile
-import six.moves.urllib.request, six.moves.urllib.parse, six.moves.urllib.error
 import re
 import time
 import datetime
@@ -1399,7 +1398,8 @@ def graph_parcours(
     # Genere graphe
     _, path = tempfile.mkstemp(".gr")
     g.write(path=path, format=format)
-    data = open(path, "rb").read()
+    with open(path, "rb") as f:
+        data = f.read()
     log("dot generated %d bytes in %s format" % (len(data), format))
     if not data:
         log("graph.to_string=%s" % g.to_string())
diff --git a/app/views/entreprises.py b/app/views/entreprises.py
index 9d1e76a0..5b8cec66 100644
--- a/app/views/entreprises.py
+++ b/app/views/entreprises.py
@@ -35,6 +35,7 @@ Note: Code très ancien, porté de Zope/DTML, peu utilisable
 
 
 import time
+import urllib
 
 from flask import request
 from flask_login import current_user
@@ -166,14 +167,14 @@ def index_html(etud_nom=None, limit=50, offset="", format="html"):
         if offset:
             webparams["offset"] = max((offset or 0) - limit, 0)
             prev_lnk = '<a class="stdlink" href="%s">précédentes</a>' % (
-                request.base_url + "?" + six.moves.urllib.parse.urlencode(webparams)
+                request.base_url + "?" + urllib.parse.urlencode(webparams)
             )
         else:
             prev_lnk = ""
         if len(entreprises) >= limit:
             webparams["offset"] = (offset or 0) + limit
             next_lnk = '<a class="stdlink" href="%s">suivantes</a>' % (
-                request.base_url + "?" + six.moves.urllib.parse.urlencode(webparams)
+                request.base_url + "?" + urllib.parse.urlencode(webparams)
             )
         else:
             next_lnk = ""
diff --git a/misc/change_enseignant.py b/misc/change_enseignant.py
deleted file mode 100755
index 438adef6..00000000
--- a/misc/change_enseignant.py
+++ /dev/null
@@ -1,57 +0,0 @@
-#!/usr/bin/env python
-# -*- coding: utf-8 -*-
-
-"""Change un identifiant d'enseignant (pour corriger une erreur, typiquement un doublon)
-
-(à lancer en tant qu'utilisateur postgres)
-Emmanuel Viennet, 2007 - 2014
-"""
-
-from __future__ import print_function
-import pdb, os, sys
-import psycopg2
-from six.moves import input
-
-if len(sys.argv) != 4:
-    print("Usage: %s database ancien_utilisateur nouvel_utilisateur" % sys.argv[0])
-    print("Exemple: change_enseignant.py SCOGEII toto tata")
-    sys.exit(1)
-
-dbname = sys.argv[1]
-OLD_ID = sys.argv[2]
-NEW_ID = sys.argv[3]
-
-DBCNXSTRING = "dbname=%s" % dbname
-
-# Confirmation
-ans = input(
-    "Remplacer le l'utilisateur %s par %s dans toute la base du departement %s ?"
-    % (OLD_ID, NEW_ID, dbname)
-).strip()
-if not ans or ans[0].lower() not in "oOyY":
-    print("annulation")
-    sys.exit(-1)
-
-
-cnx = psycopg2.connect(DBCNXSTRING)
-
-cursor = cnx.cursor()
-req = "update %s set %s=%%(new_id)s where %s=%%(old_id)s"
-args = {"old_id": OLD_ID, "new_id": NEW_ID}
-
-tables_attr = {
-    "notes_formsemestre": "responsable_id",
-    "entreprise_contact": "enseignant",
-    "admissions": "rapporteur",
-    "notes_moduleimpl": "responsable_id",
-    "notes_modules_enseignants": "ens_id",
-    "notes_notes": "uid",
-    "notes_notes_log": "uid",
-    "notes_appreciations": "author",
-}
-
-for (table, attr) in tables_attr.items():
-    cursor.execute(req % (table, attr, attr), args)
-    print("table %s:  %s" % (table, cursor.statusmessage))
-
-cnx.commit()
diff --git a/requirements-3.9.txt b/requirements-3.9.txt
index 682b0505..4c83a175 100755
--- a/requirements-3.9.txt
+++ b/requirements-3.9.txt
@@ -58,7 +58,6 @@ redis==3.5.3
 reportlab==3.6.1
 requests==2.26.0
 rq==1.9.0
-six==1.16.0
 SQLAlchemy==1.4.22
 toml==0.10.2
 urllib3==1.26.6