diff --git a/Lib/cgitb.py b/Lib/cgitb.py
index 4f81271be3ca786..98d6ccbb4351256 100644
--- a/Lib/cgitb.py
+++ b/Lib/cgitb.py
@@ -45,19 +45,19 @@ def reset():
 __UNDEF__ = []                          # a special sentinel object
 def small(text):
     if text:
-        return '<small>' + text + '</small>'
+        return f'<small>{text}</small>'
     else:
         return ''
 
 def strong(text):
     if text:
-        return '<strong>' + text + '</strong>'
+        return f'<strong>{text}</strong>'
     else:
         return ''
 
 def grey(text):
     if text:
-        return '<font color="#909090">' + text + '</font>'
+        return f'<font color="#909090">{text}</font>'
     else:
         return ''
 
@@ -91,7 +91,7 @@ def scanvars(reader, frame, locals):
                 where, value = lookup(token, frame, locals)
                 vars.append((token, where, value))
         elif token == '.':
-            prefix += lasttoken + '.'
+            prefix += f"{lasttoken}."
             parent = value
         else:
             parent, prefix = None, ''
@@ -103,6 +103,7 @@ def html(einfo, context=5):
     etype, evalue, etb = einfo
     if isinstance(etype, type):
         etype = etype.__name__
+    pyver = f'Python {sys.version.split()[0]}:{sys.executable}'
     pyver = 'Python ' + sys.version.split()[0] + ': ' + sys.executable
     date = time.ctime(time.time())
     head = '<body bgcolor="#f0f0f8">' + pydoc.html.heading(
@@ -143,8 +144,8 @@ def reader(lnum=[lnum]):
             for line in lines:
                 num = small('&nbsp;' * (5-len(str(i))) + str(i)) + '&nbsp;'
                 if i in highlight:
-                    line = '<tt>=&gt;%s%s</tt>' % (num, pydoc.html.preformat(line))
-                    rows.append('<tr><td bgcolor="#ffccee">%s</td></tr>' % line)
+                    line = f'<tt>=&gt;{num}{pydoc.html.preformat(line)}</tt>'
+                    rows.append(f'<tr><td bgcolor="#ffccee">{line}</td></tr>')
                 else:
                     line = '<tt>&nbsp;&nbsp;%s%s</tt>' % (num, pydoc.html.preformat(line))
                     rows.append('<tr><td>%s</td></tr>' % grey(line))
@@ -163,7 +164,7 @@ def reader(lnum=[lnum]):
                     name = where + strong(name.split('.')[-1])
                 dump.append('%s&nbsp;= %s' % (name, pydoc.html.repr(value)))
             else:
-                dump.append(name + ' <em>undefined</em>')
+                dump.append(f'{name} <em>undefined</em>')
 
         rows.append('<tr><td>%s</td></tr>' % small(grey(', '.join(dump))))
         frames.append('''