diff --git a/app/scodoc/sco_bulletins_generator.py b/app/scodoc/sco_bulletins_generator.py
index 6e753915..70557dfc 100644
--- a/app/scodoc/sco_bulletins_generator.py
+++ b/app/scodoc/sco_bulletins_generator.py
@@ -43,9 +43,13 @@ La préférence 'bul_pdf_class_name' est obsolete (inutilisée).
 
 """
 import time
-import cStringIO
 import collections
 import traceback
+
+try:
+    from io import StringIO  # for Python 3
+except ImportError:
+    from cStringIO import StringIO  # for Python 2
 import reportlab
 from reportlab.platypus import SimpleDocTemplate, Paragraph, Spacer, Frame, PageBreak
 from reportlab.platypus import Table, TableStyle, Image, KeepInFrame
@@ -215,7 +219,7 @@ class BulletinGenerator(object):
         else:
             # Generation du document PDF
             sem = sco_formsemestre.get_formsemestre(self.context, formsemestre_id)
-            report = cStringIO.StringIO()  # in-memory document, no disk file
+            report = StringIO.StringIO()  # in-memory document, no disk file
             document = sco_pdf.BaseDocTemplate(report)
             document.addPageTemplates(
                 sco_pdf.ScolarsPageTemplate(
diff --git a/app/scodoc/sco_bulletins_pdf.py b/app/scodoc/sco_bulletins_pdf.py
index eca31dea..f848f90b 100644
--- a/app/scodoc/sco_bulletins_pdf.py
+++ b/app/scodoc/sco_bulletins_pdf.py
@@ -54,8 +54,11 @@ import time
 import traceback
 import re
 import os
-import cStringIO
 
+try:
+    from io import StringIO  # for Python 3
+except ImportError:
+    from cStringIO import StringIO  # for Python 2
 from reportlab.platypus.doctemplate import PageTemplate, BaseDocTemplate
 
 from app.scodoc import VERSION
@@ -89,7 +92,7 @@ def pdfassemblebulletins(
         sco_preferences.get_preference(context, "bottom_margin", formsemestre_id),
     )
 
-    report = cStringIO.StringIO()  # in-memory document, no disk file
+    report = StringIO.StringIO()  # in-memory document, no disk file
     document = BaseDocTemplate(report)
     document.addPageTemplates(
         sco_pdf.ScolarsPageTemplate(
diff --git a/app/scodoc/sco_groups.py b/app/scodoc/sco_groups.py
index 96b49e60..cdef47ac 100644
--- a/app/scodoc/sco_groups.py
+++ b/app/scodoc/sco_groups.py
@@ -36,7 +36,6 @@ Optimisation possible:
 import time
 import collections
 import re
-import sets
 import operator
 
 import xml.dom.minidom
@@ -1274,7 +1273,7 @@ def groups_auto_repartition(context, partition_id=None, REQUEST=None):
         )  # > identdict
         identdict = nt.identdict
         # build:  { civilite : liste etudids trie par niveau croissant }
-        civilites = sets.Set([x["civilite"] for x in identdict.values()])
+        civilites = set([x["civilite"] for x in identdict.values()])
         listes = {}
         for civilite in civilites:
             listes[civilite] = [
diff --git a/app/scodoc/sco_pdf.py b/app/scodoc/sco_pdf.py
index a2a5f33c..66050dff 100755
--- a/app/scodoc/sco_pdf.py
+++ b/app/scodoc/sco_pdf.py
@@ -314,7 +314,7 @@ def pdf_basic_page(
     adding a title if specified.
     """
     StyleSheet = styles.getSampleStyleSheet()
-    report = cStringIO.StringIO()  # in-memory document, no disk file
+    report = StringIO.StringIO()  # in-memory document, no disk file
     document = BaseDocTemplate(report)
     document.addPageTemplates(
         ScolarsPageTemplate(
diff --git a/app/scodoc/sco_pvpdf.py b/app/scodoc/sco_pvpdf.py
index 11b9d99c..315aedec 100644
--- a/app/scodoc/sco_pvpdf.py
+++ b/app/scodoc/sco_pvpdf.py
@@ -28,9 +28,12 @@
 """Edition des PV de jury
 """
 import os
-import types
 import re
-import cStringIO
+
+try:
+    from io import StringIO  # for Python 3
+except ImportError:
+    from cStringIO import StringIO  # for Python 2
 import reportlab
 from reportlab.lib.units import cm, mm
 from reportlab.lib.enums import TA_LEFT, TA_RIGHT, TA_CENTER, TA_JUSTIFY
@@ -387,7 +390,7 @@ def pdf_lettres_individuelles(
     )
 
     # ----- Build PDF
-    report = cStringIO.StringIO()  # in-memory document, no disk file
+    report = StringIO.StringIO()  # in-memory document, no disk file
     document = BaseDocTemplate(report)
     document.addPageTemplates(
         CourrierIndividuelTemplate(
@@ -587,7 +590,7 @@ def _make_signature_image(signature, leftindent, formsemestre_id, context=None):
     # cree une image PIL pour avoir la taille (W,H)
     from PIL import Image as PILImage
 
-    f = cStringIO.StringIO(signature)
+    f = StringIO.StringIO(signature)
     im = PILImage.open(f)
     width, height = im.size
     pdfheight = (
@@ -671,7 +674,7 @@ def pvjury_pdf(
             )
 
     # ----- Build PDF
-    report = cStringIO.StringIO()  # in-memory document, no disk file
+    report = StringIO.StringIO()  # in-memory document, no disk file
     document = BaseDocTemplate(report)
     document.pagesize = landscape(A4)
     document.addPageTemplates(