diff --git a/src/pyquickhelper/helpgen/sphinxm_convert_doc_sphinx_helper.py b/src/pyquickhelper/helpgen/sphinxm_convert_doc_sphinx_helper.py
index 1eb598b8..3ae309e9 100644
--- a/src/pyquickhelper/helpgen/sphinxm_convert_doc_sphinx_helper.py
+++ b/src/pyquickhelper/helpgen/sphinxm_convert_doc_sphinx_helper.py
@@ -1240,7 +1240,7 @@ def _init_env(self, freshenv):
                     self.env.setup(self)
                 self.info('done')
             except Exception as err:
-                self.info(f'failed: {err}')
+                self.info('failed: %r', err)
                 self._init_env(freshenv=True)
         elif self.env is None:  # pragma: no cover
             self.env = _CustomBuildEnvironment(self)
@@ -1382,17 +1382,14 @@ def add_directive(self, name, obj, content=None, arguments=None,  # pylint: disa
             def run(self):
                 """Run the plot directive."""
                 logger = getLogger("MockSphinxApp")
-                logger.info(
-                    f'[MockSphinxApp] PlotDirective: {self.content}')
+                logger.info('[MockSphinxApp] PlotDirective: %r', self.content)
                 try:
                     res = old_run(self)
-                    logger.info(
-                        '[MockSphinxApp] PlotDirective ok')
+                    logger.info('[MockSphinxApp] PlotDirective ok')
                     return res
                 except OSError as e:  # pragma: no cover
                     logger = getLogger("MockSphinxApp")
-                    logger.info(
-                        f'[MockSphinxApp] PlotDirective failed: {e}')
+                    logger.info('[MockSphinxApp] PlotDirective failed: %s', e)
                 return []
 
             obj.run = run
diff --git a/src/pyquickhelper/pycode/utils_tests.py b/src/pyquickhelper/pycode/utils_tests.py
index 7ecb461f..4c1121d2 100644
--- a/src/pyquickhelper/pycode/utils_tests.py
+++ b/src/pyquickhelper/pycode/utils_tests.py
@@ -462,13 +462,10 @@ def write_covlog(covs):
     err = res.get("err", "")
     if len(err) > 0:  # pragma: no cover
         # Remove most of the Sphinx warnings (sphinx < 1.8)
-        lines = err.split("\n")
-        lines = [
-            _ for _ in lines if _ and (
-                "is already registered, it will be overridden" not in _ and
-                "has to be local relative or absolute path to image" not in _)]
-        err = "\n".join(lines)
-    if len(err) > 0:
+        fLOG("[main_wrapper_tests] EXCEPTION BEGIN")
+        fLOG(err)
+        fLOG("[main_wrapper_tests] EXCEPTION END")
+    if len(err) > 10000:
         raise TestWrappedException(err)  # pragma: no cover
 
     datetime_end = datetime.now()
diff --git a/src/pyquickhelper/sphinxext/_sphinx_common_builder.py b/src/pyquickhelper/sphinxext/_sphinx_common_builder.py
index c9037151..1c6c6444 100644
--- a/src/pyquickhelper/sphinxext/_sphinx_common_builder.py
+++ b/src/pyquickhelper/sphinxext/_sphinx_common_builder.py
@@ -148,8 +148,8 @@ def base_visit_image(self, node, image_dest=None):
                             except InternetException as e:  # pragma: no cover
                                 logger = logging.getLogger("image")
                                 logger.warning(
-                                    "[image] unable to get content for url '{0}' due to '{1}'"
-                                    "".format(atts['src'], e))
+                                    "[image] unable to get content for url %r due to %r",
+                                    atts['src'], e)
                                 this = os.path.abspath(
                                     os.path.dirname(__file__))
                                 full = os.path.join(
diff --git a/src/pyquickhelper/sphinxext/sphinx_autosignature.py b/src/pyquickhelper/sphinxext/sphinx_autosignature.py
index 64373171..8c55de83 100644
--- a/src/pyquickhelper/sphinxext/sphinx_autosignature.py
+++ b/src/pyquickhelper/sphinxext/sphinx_autosignature.py
@@ -165,8 +165,7 @@ def keep_logging(*els):
             if logging_function:
                 logging_function(mes)  # pragma: no cover
             if lineno is not None:
-                logger.warning(
-                    f'   File "{source}", line {lineno}')
+                logger.warning('   File "%s", line %r', source, lineno)
             obj = None
             kind = None
         if opt_syspath:
@@ -175,8 +174,8 @@ def keep_logging(*els):
         if opt_members is not None and kind != "class":  # pragma: no cover
             logger = logging.getLogger("autosignature")
             logger.warning(
-                "[autosignature] option members is specified but '{0}' "
-                "is not a class (kind='{1}').".format(object_name, kind))
+                "[autosignature] option members is specified but %r "
+                "is not a class (kind=%r).", object_name, kind)
             obj = None
 
         # build node
@@ -187,8 +186,8 @@ def keep_logging(*els):
         if opt_path == 'import':
             if obj is None:
                 logger = logging.getLogger("autosignature")
-                logger.warning(
-                    f"[autosignature] object '{object_name}' cannot be imported.")
+                logger.warning("[autosignature] object %r cannot be imported.",
+                               object_name)
                 anchor = object_name
             elif kind == "staticmethod":
                 cl, fu = object_name.split(".")[-2:]
@@ -205,8 +204,8 @@ def keep_logging(*els):
         else:  # pragma: no cover
             logger = logging.getLogger("autosignature")
             logger.warning(
-                "[autosignature] options path is '{0}', it should be in "
-                "(import, name, full) for object '{1}'.".format(opt_path, object_name))
+                "[autosignature] options path is %r, it should be in "
+                "(import, name, full) for object %r.", opt_path, object_name)
             anchor = object_name
 
         if obj is None:
@@ -334,7 +333,7 @@ def build_members(self, obj, members, object_name, annotation, summary):
                 logger = logging.getLogger("autosignature")
                 logger.warning(
                     "[autosignature](2) unable to get signature of "
-                    "'{0}.{1} - {2}'.".format(object_name, name, str(e).replace("\n", "\\n")))
+                    "'%s.%s - %s'.", object_name, name, str(e).replace("\n", "\\n"))
                 signature = None
             except ValueError:  # pragma: no cover
                 signature = None
@@ -355,8 +354,8 @@ def build_members(self, obj, members, object_name, annotation, summary):
                 doc = value.__doc__
                 if doc is None:  # pragma: no cover
                     logger = logging.getLogger("autosignature")
-                    logger.warning(
-                        f"[autosignature] docstring empty for '{object_name}.{name}'.")
+                    logger.warning("[autosignature] docstring empty for '%s.%s'.",
+                                   object_name, name)
                 else:
                     docstring = self.build_summary(doc)
                     lines = "\n".join(
diff --git a/src/pyquickhelper/sphinxext/sphinx_bigger_extension.py b/src/pyquickhelper/sphinxext/sphinx_bigger_extension.py
index b2f47704..34459783 100644
--- a/src/pyquickhelper/sphinxext/sphinx_bigger_extension.py
+++ b/src/pyquickhelper/sphinxext/sphinx_bigger_extension.py
@@ -117,8 +117,8 @@ def depart_bigger_node(self, node):
     depart bigger_node for format other than html
     """
     logger = getLogger("bigger")
-    logger.warning("[depart_bigger_node] output only available for HTML not for '{0}'".format(
-        type(self)))
+    logger.warning(
+        "[depart_bigger_node] output only available for HTML not for %r", type(self))
 
 
 def setup(app):
diff --git a/src/pyquickhelper/sphinxext/sphinx_blog_extension.py b/src/pyquickhelper/sphinxext/sphinx_blog_extension.py
index 44091787..cfaf1721 100644
--- a/src/pyquickhelper/sphinxext/sphinx_blog_extension.py
+++ b/src/pyquickhelper/sphinxext/sphinx_blog_extension.py
@@ -173,7 +173,7 @@ def fill_node(self, node, env, tag, p, language_code, targetnode, sharepost):
             from sphinx.util import logging
             logger = logging.getLogger("blogpost")
             logger.warning(
-                f"[blogpost] unable to parse '{title}' - {e}")
+                "[blogpost] unable to parse %r - %s", title, e)
             raise e
 
         # final
diff --git a/src/pyquickhelper/sphinxext/sphinx_cmdref_extension.py b/src/pyquickhelper/sphinxext/sphinx_cmdref_extension.py
index fc66b16f..ce790dcb 100644
--- a/src/pyquickhelper/sphinxext/sphinx_cmdref_extension.py
+++ b/src/pyquickhelper/sphinxext/sphinx_cmdref_extension.py
@@ -106,11 +106,11 @@ def run(self):
                     out = "--SCRIPT--{}\n--OUT--\n{}\n--ERR--\n{}\n--PATH--\n{}".format(
                         name, out, err, path)
                     logger = logging.getLogger("CmdRef")
-                    logger.warning(f"[CmdRef] cmd failed '{name}'")
+                    logger.warning("[CmdRef] cmd failed %r", name)
                 elif out in (None, ''):
                     out = f"--SCRIPT--{name}\n--EMPTY OUTPUT--\n--PATH--\n{path}"
                     logger = logging.getLogger("CmdRef")
-                    logger.warning(f"[CmdRef] cmd empty '{name}'")
+                    logger.warning("[CmdRef] cmd empty %r", name)
                 content = "python " + name
                 cont += nodes.paragraph('<<<', '<<<')
                 pout = nodes.literal_block(content, content)
@@ -122,20 +122,22 @@ def run(self):
                 if ":" not in name:
                     logger = logging.getLogger("CmdRef")
                     logger.warning(
-                        f"[CmdRef] cmd '{name}' should contain ':': <full_function_name>:<cmd_name> as specified in the setup.")
+                        "[CmdRef] cmd %r should contain ':': "
+                        "<full_function_name>:<cmd_name> as specified in the setup.",
+                        name)
                     if lineno is not None:
-                        logger.warning(
-                            f'   File "{source}", line {lineno}')
+                        logger.warning('   File "%s", line %r', source, lineno)
 
                 # example: pyquickhelper.cli.pyq_sync_cli:pyq_sync
                 spl = name.strip("\r\n\t ").split(":")
                 if len(spl) != 2:  # pragma: no cover
                     logger = logging.getLogger("CmdRef")
                     logger.warning(
-                        f"[CmdRef] cmd(*= '{name}' should contain ':': <full_function_name>:<cmd_name> as specified in the setup.")
+                        "[CmdRef] cmd(*= %r should contain ':': "
+                        "<full_function_name>:<cmd_name> as specified in the setup.",
+                        name)
                     if lineno is not None:
-                        logger.warning(
-                            f'   File "{source}", line {lineno}')
+                        logger.warning('   File "%s", line %r', source, lineno)
 
                 # rename the command line
                 if "=" in spl[0]:
@@ -154,11 +156,9 @@ def run(self):
                     obj, name = import_object(fullname, kind="function")
                 except ImportError:  # pragma: no cover
                     logger = logging.getLogger("CmdRef")
-                    logger.warning(
-                        f"[CmdRef] unable to import '{fullname}'")
+                    logger.warning("[CmdRef] unable to import %r", fullname)
                     if lineno is not None:
-                        logger.warning(
-                            f'   File "{source}", line {lineno}')
+                        logger.warning('   File "%s", line %r', source, lineno)
                     obj = None
 
                 if obj is not None:
@@ -177,13 +177,13 @@ def local_print(*li):
                     if len(content) == 0:  # pragma: no cover
                         logger = logging.getLogger("CmdRef")
                         logger.warning(
-                            f"[CmdRef] empty output for '{fullname}'")
+                            "[CmdRef] empty output for %r", fullname)
                         if lineno is not None:
                             logger.warning(
-                                f'   File "{source}", line {lineno}')
+                                '   File "%s", line %r', source, lineno)
                         out = f"--SCRIPT--{name}\n--EMPTY OUTPUT--\n--PATH--\n{path}"
                         logger = logging.getLogger("CmdRef")
-                        logger.warning(f"[CmdRef] cmd empty '{name}'")
+                        logger.warning("[CmdRef] cmd empty %r", name)
                     else:
                         start = 'usage: ' + name_fct
                         if content.startswith(start):
diff --git a/src/pyquickhelper/sphinxext/sphinx_docassert_extension.py b/src/pyquickhelper/sphinxext/sphinx_docassert_extension.py
index e3c1a4e5..2ede1206 100644
--- a/src/pyquickhelper/sphinxext/sphinx_docassert_extension.py
+++ b/src/pyquickhelper/sphinxext/sphinx_docassert_extension.py
@@ -15,7 +15,8 @@ def check_typed_make_field(self, types, domain, items, env=None, parameters=None
                            function_name=None, docname=None, kind=None):
     """
     Overwrites function
-    `make_field <https://github.com/sphinx-doc/sphinx/blob/master/sphinx/util/docfields.py#L197>`_.
+    #L197>`_.
+    `make_field <https://github.com/sphinx-doc/sphinx/blob/master/sphinx/util/docfields.py
     Processes one argument of a function.
 
     @param      self            from original function
@@ -54,13 +55,13 @@ def check_item(fieldarg, content, logger):
         "local function"
         if fieldarg not in check_params:
             if function_name is not None:
-                logger.warning("[docassert] '{0}' has no parameter '{1}' (in '{2}').".format(
-                    function_name, fieldarg, docname))
+                logger.warning("[docassert] %r has no parameter %r (in %r).",
+                               function_name, fieldarg, docname)
         else:
             check_params[fieldarg] += 1
             if check_params[fieldarg] > 1:
-                logger.warning("[docassert] '{1}' of '{0}' is duplicated (in '{2}').".format(
-                    function_name, fieldarg, docname))
+                logger.warning("[docassert] %r of %r is duplicated (in %r).",
+                               fieldarg, function_name, docname)
 
     if isinstance(items, list):
         for fieldarg, content in items:
@@ -74,8 +75,8 @@ def check_item(fieldarg, content, logger):
                     # Behavior should be improved.
                     pass
                 else:
-                    logger.warning("[docassert] '{0}' has undocumented parameters '{1}' (in '{2}').".format(
-                        function_name, ", ".join(nodoc), docname))
+                    logger.warning("[docassert] %r has undocumented parameters %r (in %r).",
+                                   function_name, ", ".join(nodoc), docname)
     else:
         # Documentation related to the return.
         pass
@@ -208,8 +209,8 @@ def override_transform(self, other_self, node):
                 else:
                     reasons = "unknown"
                 logger = logging.getLogger("docassert")
-                logger.warning(
-                    f"[docassert] unable to import object '{docs}', reasons:\n{reasons}")
+                logger.warning("[docassert] unable to import object %r, reasons:\n%s",
+                               docs, reasons)
                 myfunc = None
 
             if myfunc is None:
@@ -222,7 +223,7 @@ def override_transform(self, other_self, node):
                 except (TypeError, ValueError):
                     logger = logging.getLogger("docassert")
                     logger.warning(
-                        f"[docassert] unable to get signature of '{docs}'.")
+                        "[docassert] unable to get signature of %r.", docs)
                     signature = None
                     parameters = None
 
@@ -253,7 +254,7 @@ def override_transform(self, other_self, node):
             env = other_self.directive.state.document.settings.env
         except AttributeError as e:
             logger = logging.getLogger("docassert")
-            logger.warning(f"[docassert] {e}")
+            logger.warning("[docassert] %s", e)
             env = None
 
         docname = fieldbody.parent.source.split(':docstring')[0]
@@ -262,7 +263,7 @@ def override_transform(self, other_self, node):
             if isinstance(entry, nodes.field):
                 logger = logging.getLogger("docassert")
                 logger.warning(
-                    f"[docassert] unable to check [nodes.field] {entry}")
+                    "[docassert] unable to check [nodes.field] %s", entry)
             else:
                 fieldtype, content = entry
                 fieldtypes = types.get(fieldtype.name, {})
diff --git a/src/pyquickhelper/sphinxext/sphinx_doctree_builder.py b/src/pyquickhelper/sphinxext/sphinx_doctree_builder.py
index 660e5d76..1fd6d0e1 100644
--- a/src/pyquickhelper/sphinxext/sphinx_doctree_builder.py
+++ b/src/pyquickhelper/sphinxext/sphinx_doctree_builder.py
@@ -48,8 +48,7 @@ def __init__(self, document, builder):
 
     def log_unknown(self, type, node):
         logger = logging.getLogger("DocTreeBuilder")
-        logger.warning(
-            f"[doctree] {type}({node}) unsupported formatting")
+        logger.warning("[doctree] %s(%s) unsupported formatting", type, node)
 
     def wrap(self, text, width=STDINDENT):
         self.wrapper.width = width
diff --git a/src/pyquickhelper/sphinxext/sphinx_downloadlink_extension.py b/src/pyquickhelper/sphinxext/sphinx_downloadlink_extension.py
index 05ebe311..3b4fd81d 100644
--- a/src/pyquickhelper/sphinxext/sphinx_downloadlink_extension.py
+++ b/src/pyquickhelper/sphinxext/sphinx_downloadlink_extension.py
@@ -110,7 +110,7 @@ def process_downloadlink_role(role, rawtext, text, lineno, inliner, options=None
     node['anchor'] = anchor
 
     logger = logging.getLogger("downloadlink")
-    logger.info(f"[downloadlink] node '{str(node)}'")
+    logger.info("[downloadlink] node %s", node)
 
     return [node], []
 
@@ -123,7 +123,7 @@ def visit_downloadlink_node_html(self, node):
         raise nodes.SkipNode
 
     logger = logging.getLogger("downloadlink")
-    logger.info(f"[downloadlink] HTML '{str(node)}'")
+    logger.info("[downloadlink] HTML %s", node)
 
     atts = {'class': 'reference'}
 
@@ -187,7 +187,7 @@ def visit_downloadlink_node_rst(self, node):
     Converts node *downloadlink* into :epkg:`rst`.
     """
     logger = logging.getLogger("downloadlink")
-    logger.info(f"[downloadlink] RST '{str(node)}'")
+    logger.info("[downloadlink] RST %s", node)
 
     if node['format']:
         self.add_text(":downloadlink:`{0} <{1}::{2}>`".format(
@@ -255,7 +255,7 @@ def process_doc(self, app, doctree):
                 app.env.docname, rel_filename)
         if nb > 0:
             logger = logging.getLogger("downloadlink")
-            logger.info(f"[downloadlink] processed {nb}")
+            logger.info("[downloadlink] processed %r", nb)
 
 
 def copy_download_files(app, exc):
@@ -291,13 +291,12 @@ def to_relpath(f):
                 name = os.path.join(builder.srcdir, src)
                 try:
                     copyfile(name, dest)
-                    logger.info(
-                        f"[downloadlink] copy '{name}' to '{dest}'")
+                    logger.info("[downloadlink] copy %r to %r", name, dest)
                 except FileNotFoundError:
                     mes = "Builder format '{0}'-'{3}', unable to copy file '{1}' into {2}'".format(
                         builder.format, name, dest, builder.__class__.__name__)
                     logger.warning(
-                        f"[downloadlink] cannot copy '{name}' to '{dest}'")
+                        "[downloadlink] cannot copy %r to %r", name, dest)
 
 
 def setup(app):
diff --git a/src/pyquickhelper/sphinxext/sphinx_gdot_extension.py b/src/pyquickhelper/sphinxext/sphinx_gdot_extension.py
index 35021f80..6ffce13b 100644
--- a/src/pyquickhelper/sphinxext/sphinx_gdot_extension.py
+++ b/src/pyquickhelper/sphinxext/sphinx_gdot_extension.py
@@ -134,7 +134,7 @@ def run(self):
                 url = GDotDirective._default_url
                 logger = logging.getLogger("gdot")
                 logger.warning("[gdot] jyquickhelper not installed, falling back to "
-                               "'{}'".format(url))
+                               "%r", url)
 
         info = get_env_state_info(self)
         docname = info['docname']
@@ -142,7 +142,8 @@ def run(self):
             if docname is None or 'HERE' not in info:
                 url = GDotDirective._default_url
                 logger = logging.getLogger("gdot")
-                logger.warning("[gdot] docname is none, falling back to %r.", url)
+                logger.warning(
+                    "[gdot] docname is none, falling back to %r.", url)
             else:
                 spl = docname.split("/")
                 sp = ['..'] * (len(spl) - 1) + ['_static', 'viz.js']
@@ -291,27 +292,26 @@ def copy_js_files(app):
                         dest = os.path.join(destf, 'viz.js')
                         try:
                             shutil.copy(path, dest)
-                            logger.info(
-                                f"[gdot] copy '{path}' to '{dest}'.")
+                            logger.info("[gdot] copy %r to %r.", path, dest)
                         except PermissionError as e:  # pragma: no cover
-                            logger.warning("[gdot] permission error: {}, "
-                                           "unable to use local viz.js.".format(e))
+                            logger.warning("[gdot] permission error: %e, "
+                                           "unable to use local viz.js.", e)
 
                         if not os.path.exists(dest):
-                            logger.warning("[gdot] unable to copy='{}', "
-                                           "unable to use local viz.js.".format(dest))
+                            logger.warning("[gdot] unable to copy=%r, "
+                                           "unable to use local viz.js.", dest)
                     else:
-                        logger.warning("[gdot] destination folder='{}' does not exists, "
-                                       "unable to use local viz.js.".format(destf))
+                        logger.warning("[gdot] destination folder=%r does not exists, "
+                                       "unable to use local viz.js.", destf)
                 else:
-                    logger.warning("[gdot] unable to locate html_static_path='{}', "
-                                   "unable to use local viz.js.".format(app.config.html_static_path))
+                    logger.warning("[gdot] unable to locate html_static_path=%r, "
+                                   "unable to use local viz.js.", app.config.html_static_path)
         else:
-            logger.warning("[gdot] jyquickhelper needs to be update, unable to find '{}'.".format(
-                path))
+            logger.warning(
+                "[gdot] jyquickhelper needs to be update, unable to find %r.", path)
     else:
         logger.warning("[gdot] jyquickhelper not installed, falling back to "
-                       "'{}'".format(GDotDirective._default_url))
+                       "%r", GDotDirective._default_url)
 
 
 def setup(app):
diff --git a/src/pyquickhelper/sphinxext/sphinx_gitlog_extension.py b/src/pyquickhelper/sphinxext/sphinx_gitlog_extension.py
index 4671f2d1..bdfec98d 100644
--- a/src/pyquickhelper/sphinxext/sphinx_gitlog_extension.py
+++ b/src/pyquickhelper/sphinxext/sphinx_gitlog_extension.py
@@ -120,8 +120,8 @@ def depart_gitlog_node(self, node):
     depart *gitlog_node* for format other than html
     """
     logger = getLogger("gitlog")
-    logger.warning("[depart_gitlog_node] output only available for HTML not for '{0}'".format(
-        type(self)))
+    logger.warning(
+        "[depart_gitlog_node] output only available for HTML not for %r", type(self))
 
 
 def setup(app):
diff --git a/src/pyquickhelper/sphinxext/sphinx_image_extension.py b/src/pyquickhelper/sphinxext/sphinx_image_extension.py
index 590b821d..1b10b634 100644
--- a/src/pyquickhelper/sphinxext/sphinx_image_extension.py
+++ b/src/pyquickhelper/sphinxext/sphinx_image_extension.py
@@ -79,8 +79,8 @@ def run(self):
         if '://' in filename:
             logger = getLogger("simpleimage")  # pragma: no cover
             logger.warning(  # pragma: no cover
-                "[simpleimage] url detected '{0}' in docname '{1}' - line {2}"
-                ".".format(filename, docname, self.lineno))
+                "[simpleimage] url detected %r in docname %r - line %r"
+                ".", filename, docname, self.lineno)
             is_url = True
         else:
             is_url = False
@@ -89,15 +89,16 @@ def run(self):
         if convert:
             logger = getLogger("simpleimage")  # pragma: no cover
             logger.warning(  # pragma: no cover
-                "[simpleimage] convert into '{3}' not implemented for '{0}' in "
-                "docname '{1}' - line {2}.".format(
-                    filename, docname, self.lineno, convert))
+                "[simpleimage] convert into %r not implemented for %r in "
+                "docname %r - line %r.",
+                convert, filename, docname, self.lineno)
 
         download = self.options.get('download', None)
         if convert:
             logger = getLogger("simpleimage")
             logger.warning(  # pragma: no cover
-                f"[simpleimage] download not implemented for '{filename}' in docname '{docname}' - line {self.lineno}.")
+                "[simpleimage] download not implemented for %r in docname %r - line %r.",
+                filename, docname, self.lineno)
 
         if not is_url:
             env.images_mapping.add_file('', filename)
@@ -123,8 +124,8 @@ def run(self):
             if abspath is None:
                 logger = getLogger("simpleimage")  # pragma: no cover
                 logger.warning(  # pragma: no cover
-                    "[simpleimage] Unable to find '{0}' in docname '{1}' - line {2} - srcdir='{3}'.".format(
-                        filename, docname, self.lineno, srcdir))
+                    "[simpleimage] Unable to find %r in docname %r - line %r - srcdir=%r.",
+                    filename, docname, self.lineno, srcdir)
         else:
             abspath = None
             relpath = None
diff --git a/src/pyquickhelper/sphinxext/sphinx_latex_builder.py b/src/pyquickhelper/sphinxext/sphinx_latex_builder.py
index e8a5f547..67510397 100644
--- a/src/pyquickhelper/sphinxext/sphinx_latex_builder.py
+++ b/src/pyquickhelper/sphinxext/sphinx_latex_builder.py
@@ -44,8 +44,8 @@ def __init__(self, document, builder, theme=None):
             LaTeXTranslator.__init__(self, document, builder, theme=theme)
         except TypeError:
             # Sphinx<5
-            LaTeXTranslator.__init__(
-                self, document, builder)  # pylint: disable=E1120
+            LaTeXTranslator.__init__(  # pylint: disable=E1120
+                self, document, builder)
 
         newlines = builder.config.text_newlines
         if newlines == 'windows':
@@ -182,8 +182,8 @@ def depart_imgsgnode(self, node):
 
     def unknown_visit(self, node):
         logger = logging.getLogger("MdBuilder")
-        logger.warning("[latex] unknown visit node: '{0}' - '{1}'".format(
-            node.__class__.__name__, node))
+        logger.warning("[latex] unknown visit node: %r - %r",
+                       node.__class__.__name__, node)
 
 
 class EnhancedLaTeXWriter(LaTeXWriter):
@@ -289,8 +289,7 @@ def write(self, *ignored):
             doctree.settings.docname = docname
             doctree.settings.docclass = docclass
             docwriter.write(doctree, destination)
-            self.logger.info(
-                f"[EnhancedLaTeXBuilder] done in '{targetname}'")
+            self.logger.info("[EnhancedLaTeXBuilder] done in %r", targetname)
 
 
 def setup(app):
diff --git a/src/pyquickhelper/sphinxext/sphinx_md_builder.py b/src/pyquickhelper/sphinxext/sphinx_md_builder.py
index 8e7cc46c..7ea26083 100644
--- a/src/pyquickhelper/sphinxext/sphinx_md_builder.py
+++ b/src/pyquickhelper/sphinxext/sphinx_md_builder.py
@@ -82,7 +82,7 @@ def __init__(self, document, builder):
 
     def log_unknown(self, type, node):
         logger = logging.getLogger("MdBuilder")
-        logger.warning(f"{type}({node}) unsupported formatting")
+        logger.warning("%s(%r) unsupported formatting", type, node)
 
     def wrap(self, text, width=STDINDENT):
         self.wrapper.width = width
@@ -979,8 +979,8 @@ def depart_imgsgnode(self, node):
 
     def unknown_visit(self, node):
         logger = logging.getLogger("MdBuilder")
-        logger.warning("[md] unknown visit node: '{0}' - '{1}'".format(
-            node.__class__.__name__, node))
+        logger.warning("[md] unknown visit node: %r - %r",
+                       node.__class__.__name__, node)
 
 
 class MdBuilder(Builder):
diff --git a/src/pyquickhelper/sphinxext/sphinx_postcontents_extension.py b/src/pyquickhelper/sphinxext/sphinx_postcontents_extension.py
index bd4208a5..a6480d9b 100644
--- a/src/pyquickhelper/sphinxext/sphinx_postcontents_extension.py
+++ b/src/pyquickhelper/sphinxext/sphinx_postcontents_extension.py
@@ -136,7 +136,7 @@ def _modify_postcontents(node, event):
             if nid in memo:
                 raise KeyError(  # pragma: no cover
                     f"node was already added '{nid}'")
-            logger.info(f"[{event}]  {'  ' * level}section id '{nid}'")
+            logger.info("[%r]  %ssection id %r", event, '  ' * level, nid)
             level += 1
             memo[nid] = subnode
             bli = nodes.bullet_list()
@@ -144,7 +144,8 @@ def _modify_postcontents(node, event):
             roots.append(bli)
             sections.append(subnode)
         elif isinstance(subnode, nodes.title):
-            logger.info(f"[{event}]  {'  ' * level}title '{subnode.astext()}'")
+            logger.info("[%r]  %stitle %r", event,
+                        '  ' * level, subnode.astext())
             par = nodes.paragraph()
             ref = nodes.reference(refid=sections[-1]["ids"][0],
                                   reftitle=subnode.astext(),
@@ -159,8 +160,8 @@ def _modify_postcontents(node, event):
                 ids = None if len(parent["ids"]) == 0 else parent["ids"][0]
                 if ids in memo:
                     level -= 1
-                    logger.info("[{}]  {}end of section '{}'".format(
-                        event, "  " * level, parent["ids"]))
+                    logger.info("[%r]  %send of section %r",
+                                event, "  " * level, parent["ids"])
                     sections.pop()
                     roots.pop()
 
@@ -198,8 +199,8 @@ def transform_postcontents(app, doctree, fromdocname):
 
     for node in post_list:
         if node["pcprocessed"] != 1:
-            logger.warning("[postcontents] no first loop was ever processed: 'pcprocessed'={0} , File '{1}', line {2}".format(
-                node["pcprocessed"], node["pcdocname"], node["pclineno"]))
+            logger.warning("[postcontents] no first loop was ever processed: 'pcprocessed'=%s , File %r, line %r",
+                           node["pcprocessed"], node["pcdocname"], node["pclineno"])
             continue
         if len(node.children) > 0:
             # already processed
diff --git a/src/pyquickhelper/sphinxext/sphinx_quote_extension.py b/src/pyquickhelper/sphinxext/sphinx_quote_extension.py
index bd8e6cbe..16d0061f 100644
--- a/src/pyquickhelper/sphinxext/sphinx_quote_extension.py
+++ b/src/pyquickhelper/sphinxext/sphinx_quote_extension.py
@@ -231,7 +231,7 @@ def __(text):
             from sphinx.util import logging
             logger = logging.getLogger("blogpost")
             logger.warning(
-                f"[blogpost] unable to parse '{author}' - '{book or manga}' - {e}")
+                "[blogpost] unable to parse %r - %r - %r", author, book or manga, e)
             raise e
 
         node['tag'] = tag
diff --git a/src/pyquickhelper/sphinxext/sphinx_rst_builder.py b/src/pyquickhelper/sphinxext/sphinx_rst_builder.py
index bab958c8..fd3b079e 100644
--- a/src/pyquickhelper/sphinxext/sphinx_rst_builder.py
+++ b/src/pyquickhelper/sphinxext/sphinx_rst_builder.py
@@ -92,7 +92,7 @@ def __init__(self, document, builder):
 
     def log_unknown(self, type, node):
         logger = logging.getLogger("RstBuilder")
-        logger.warning(f"[rst] {type}({node}) unsupported formatting")
+        logger.warning("[rst] %s(%s) unsupported formatting", type, node)
 
     def wrap(self, text, width=STDINDENT):
         self.wrapper.width = width
@@ -1101,8 +1101,8 @@ def unknown_visit(self, node):
             # due to jupyter_sphinx
             return
         logger = logging.getLogger("RstBuilder")
-        logger.warning("[rst] unknown visit node: '{0}' - '{1}'".format(
-            node.__class__.__name__, node))
+        logger.warning("[rst] unknown visit node: '%r - %r",
+                       node.__class__.__name__, node)
 
     def unknown_departure(self, node):
         classname = node.__class__.__name__
@@ -1114,8 +1114,8 @@ def unknown_departure(self, node):
             # due to jupyter_sphinx
             return
         logger = logging.getLogger("RstBuilder")
-        logger.warning("[rst] unknown depart node: '{0}' - '{1}'".format(
-            node.__class__.__name__, node))
+        logger.warning("[rst] unknown depart node: %r - %r",
+                       node.__class__.__name__, node)
 
 
 class _BodyPlaceholder:
@@ -1129,10 +1129,10 @@ def append(self, element):
             if len(el) > 50:
                 el = el[:50] + "..."
             self.logger.warning(
-                f"[rst] body.append was called with string {el!r}.")
+                "[rst] body.append was called with string %r", el)
         else:
             self.logger.warning(
-                f"[rst] body.append was called with type {type(element)!r}.")
+                "[rst] body.append was called with type %", type(element))
         self.lines.append(element)
 
 
diff --git a/src/pyquickhelper/sphinxext/sphinx_tocdelay_extension.py b/src/pyquickhelper/sphinxext/sphinx_tocdelay_extension.py
index 8c54e3c5..fe7679c7 100644
--- a/src/pyquickhelper/sphinxext/sphinx_tocdelay_extension.py
+++ b/src/pyquickhelper/sphinxext/sphinx_tocdelay_extension.py
@@ -192,12 +192,10 @@ def transform_tocdelay(app, doctree, fromdocname):
 
     for node in post_list:
         if node["tdprocessed"] == 0:
-            logger.warning("[tocdelay] no first loop was ever processed: 'tdprocessed'={0} , File '{1}', line {2}".format(
-                node["tdprocessed"], node["tddocname"], node["tdlineno"]))
+            logger.warning("[tocdelay] no first loop was ever processed: 'tdprocessed'=%s , File %r, line %s",
+                           node["tdprocessed"], node["tddocname"], node["tdlineno"])
             continue
         if node["tdprocessed"] > 1:
-            # logger.warning("[tocdelay] already processed: 'tdprocessed'={0} , File '{1}', line {2}".format(
-            #     node["tdprocessed"], node["tddocname"], node["tdlineno"]))
             continue
 
         docs = node["tddocuments"]
@@ -214,8 +212,8 @@ def transform_tocdelay(app, doctree, fromdocname):
         dirdocname = os.path.dirname(nodedocname)
         clname, toctitle, tocid, tocdoc = node["tdrule"]
 
-        logger.info("[tocdelay] transform_tocdelay '{0}' from '{1}'".format(
-            nodedocname, fromdocname))
+        logger.info("[tocdelay] transform_tocdelay %r from %r",
+                    nodedocname, fromdocname)
         node["tdprocessed"] += 1
 
         for name, subname, extitle in docs:
@@ -228,8 +226,8 @@ def transform_tocdelay(app, doctree, fromdocname):
             subname = f"{dirdocname}/{name}"
             doc_doctree = env.get_doctree(subname)
             if doc_doctree is None:
-                logger.info("[tocdelay] ERROR (4): No doctree found for '{0}' from '{1}'".format(
-                    subname, nodedocname))
+                logger.info("[tocdelay] ERROR (4): No doctree found for %r from %r",
+                            subname, nodedocname)
 
             # It finds a node sharing the same name.
             diginto = []
@@ -238,7 +236,7 @@ def transform_tocdelay(app, doctree, fromdocname):
                     diginto.append(n)
             if len(diginto) == 0:
                 logger.info(
-                    f"[tocdelay] ERROR (3): No node '{clname}' found for '{subname}'")
+                    "[tocdelay] ERROR (3): No node %r found for %r", clname, subname)
                 continue
 
             # It takes the first one available.
@@ -251,19 +249,19 @@ def transform_tocdelay(app, doctree, fromdocname):
                 found = list(
                     sorted(set(map(lambda x: x.__class__.__name__, diginto))))
                 ext = diginto[0].attributes if len(diginto) > 0 else ""
-                logger.warning("[tocdelay] ERROR (2): Unable to find node '{0}' in {1} [{2}]".format(
-                    subname, ", ".join(map(str, found)), ext))
+                logger.warning("[tocdelay] ERROR (2): Unable to find node %r in %s [%r]",
+                               subname, ", ".join(map(str, found)), ext)
                 continue
 
             rootnode = subnode
 
             if tocid not in rootnode.attributes:
                 logger.warning(
-                    f"[tocdelay] ERROR (7): Unable to find 'tocid' in '{rootnode}'")
+                    "[tocdelay] ERROR (7): Unable to find 'tocid' in %r", rootnode)
                 continue
             if tocdoc not in rootnode.attributes:
                 logger.warning(
-                    f"[tocdelay] ERROR (8): Unable to find 'tocdoc' in '{rootnode}'")
+                    "[tocdelay] ERROR (8): Unable to find 'tocdoc' in %r", rootnode)
                 continue
             refid = rootnode[tocid]
             refdoc = rootnode[tocdoc]
@@ -271,18 +269,18 @@ def transform_tocdelay(app, doctree, fromdocname):
             subnode = list(rootnode.traverse(nodes.title))
             if not subnode:
                 logger.warning(
-                    f"[tocdelay] ERROR (5): Unable to find a title in '{subname}'")
+                    "[tocdelay] ERROR (5): Unable to find a title in %r", subname)
                 continue
             subnode = subnode[0]
 
             try:
                 refuri = app.builder.get_relative_uri(nodedocname, refdoc)
-                logger.info(
-                    f"[tocdelay] add link for '{refid}' - '{refdoc}' from '{nodedocname}'")
+                logger.info("[tocdelay] add link for %r - %r from %r",
+                            refid, refdoc, nodedocname)
             except NoUri:
                 docn = list(sorted(app.builder.docnames))
-                logger.info("[tocdelay] ERROR (9): unable to find a link for '{0}' - '{1}' from '{2}` -- {3} - {4}".format(
-                    refid, refdoc, nodedocname, type(app.builder), docn))
+                logger.info("[tocdelay] ERROR (9): unable to find a link for %r - %r from %r -- %s - %s",
+                            refid, refdoc, nodedocname, type(app.builder), docn)
                 refuri = ''
 
             use_title = extitle or subnode.astext()
@@ -300,11 +298,10 @@ def transform_tocdelay(app, doctree, fromdocname):
 def _print_loop_on_children(node, indent="", msg="-"):
     logger = logging.getLogger("tocdelay")
     if hasattr(node, "children"):
-        logger.info(
-            f"[tocdelay] '{type(node)}' - {msg} - {node}")
+        logger.info("[tocdelay] %r - %s - %s", type(node), msg, node)
         for child in node.children:
-            logger.info("[tocdelay]       {0}{1} - '{2}'".format(indent, type(child),
-                                                                 child.astext().replace("\n", " #EOL# ")))
+            logger.info("[tocdelay]       %s%s - %r",
+                        indent, type(child), child.astext().replace("\n", " #EOL# "))
             _print_loop_on_children(child, indent + "    ")
 
 
diff --git a/src/pyquickhelper/sphinxext/sphinx_toctree_extension.py b/src/pyquickhelper/sphinxext/sphinx_toctree_extension.py
index 3ee7a87a..69044b69 100644
--- a/src/pyquickhelper/sphinxext/sphinx_toctree_extension.py
+++ b/src/pyquickhelper/sphinxext/sphinx_toctree_extension.py
@@ -1,7 +1,8 @@
 # -*- coding: utf-8 -*-
 """
 @file
-@brief Overwrites `toctree <https://www.sphinx-doc.org/en/master/markup/toctree.html#directive-toctree>`_
+#directive-toctree>`_
+@brief Overwrites `toctree <https://www.sphinx-doc.org/en/master/markup/toctree.html
 directive to get catch exceptions when a document is processed inline.
 """
 from docutils.parsers.rst import directives
@@ -65,8 +66,8 @@ def run(self):
             else:
                 logger = logging.getLogger("CustomTocTreeCollector")
                 logger.warning(
-                    "[CustomTocTreeCollector] unable to remove document '{0}' from {1}".format(
-                        env.docname, ", ".join(all_docnames)))
+                    "[CustomTocTreeCollector] unable to remove document %r from %s",
+                    env.docname, ", ".join(all_docnames))
 
         for entry in self.content:
             if not entry:
@@ -208,7 +209,7 @@ def build_toc(node, depth=1):
                         an = "unkown-anchor"
                         logger = logging.getLogger("CustomTocTreeCollector")
                         logger.warning(
-                            f"[CustomTocTreeCollector] no id for node '{sectionnode}'")
+                            "[CustomTocTreeCollector] no id for node %r", sectionnode)
                     else:
                         an = sectionnode['ids'][0]
                     anchorname = '#' + an
diff --git a/src/pyquickhelper/sphinxext/sphinx_video_extension.py b/src/pyquickhelper/sphinxext/sphinx_video_extension.py
index 9b26b948..123571e5 100644
--- a/src/pyquickhelper/sphinxext/sphinx_video_extension.py
+++ b/src/pyquickhelper/sphinxext/sphinx_video_extension.py
@@ -71,7 +71,8 @@ def run(self):
         if '://' in filename:
             logger = getLogger("video")
             logger.warning(
-                f"[video] url detected '{filename}' in docname '{docname}' - line {self.lineno}.")
+                "[video] url detected %r in docname %r - line %r.",
+                filename, docname, self.lineno)
             is_url = True
         else:
             is_url = False
@@ -100,7 +101,8 @@ def run(self):
             if abspath is None:
                 logger = getLogger("video")
                 logger.warning(
-                    f"[video] Unable to find '{filename}' in docname '{docname}' - line {self.lineno} - srcdir='{srcdir}'.")
+                    "[video] Unable to find %r in docname %r - line %r - srcdir=%r.",
+                    filename, docname, self.lineno, srcdir)
         else:
             abspath = None
             relpath = None
@@ -136,7 +138,7 @@ def visit_video_node(self, node):
             os.makedirs(relpath)
         shutil.copy(node['abspath'], relpath)
         logger = getLogger("video")
-        logger.info(f"[video] copy '{node['uri']}' to '{relpath}'")
+        logger.info("[video] copy %r to %r", node['uri'], relpath)
 
 
 def _clean_value(val):
diff --git a/src/pyquickhelper/sphinxext/sphinx_youtube_extension.py b/src/pyquickhelper/sphinxext/sphinx_youtube_extension.py
index 0ed4ae0f..ff771039 100644
--- a/src/pyquickhelper/sphinxext/sphinx_youtube_extension.py
+++ b/src/pyquickhelper/sphinxext/sphinx_youtube_extension.py
@@ -145,7 +145,8 @@ def run(self):
                     lineno = self.lineno
                     docname = None if env is None else env.docname
                     logger.warning(
-                        f"[youtube] unable to extract video id from '{idurl}' in docname '{docname}' - line {lineno}.")
+                        "[youtube] unable to extract video id from %r in docname %r - line %r.",
+                        idurl, docname, lineno)
                     uid = ""
         else:
             uid = self.arguments[0]