diff --git a/csp.py b/csp.py
index f300cb816..207576928 100644
--- a/csp.py
+++ b/csp.py
@@ -344,7 +344,7 @@ def __init__(self, value): self.value = value
 
     def __getitem__(self, key): return self.value
 
-    def __repr__(self): return '{Any: %r}' % self.value
+    def __repr__(self): return '{{Any: {0!r}}}'.format(self.value)
 
 
 def different_values_constraint(A, a, B, b):
diff --git a/games.py b/games.py
index 90604bf69..9b98c5638 100644
--- a/games.py
+++ b/games.py
@@ -203,7 +203,7 @@ def display(self, state):
         print(state)
 
     def __repr__(self):
-        return '<%s>' % self.__class__.__name__
+        return '<{}>'.format(self.__class__.__name__)
 
 
 class Fig52Game(Game):
diff --git a/learning.py b/learning.py
index 0894b2190..41dd324e5 100644
--- a/learning.py
+++ b/learning.py
@@ -139,8 +139,8 @@ def check_example(self, example):
         if self.values:
             for a in self.attrs:
                 if example[a] not in self.values[a]:
-                    raise ValueError('Bad value %s for attribute %s in %s' %
-                                     (example[a], self.attrnames[a], example))
+                    raise ValueError('Bad value {} for attribute {} in {}'
+                                     .format(example[a], self.attrnames[a], example))
 
     def attrnum(self, attr):
         "Returns the number used for attr, which can be a name, or -n .. n-1."
@@ -157,7 +157,7 @@ def sanitize(self, example):
                 for i, attr_i in enumerate(example)]
 
     def __repr__(self):
-        return '<DataSet(%s): %d examples, %d attributes>' % (
+        return '<DataSet({}): {:d} examples, {:d} attributes>'.format(
             self.name, len(self.examples), len(self.attrs))
 
 # ______________________________________________________________________________
@@ -317,8 +317,8 @@ def display(self, indent=0):
             subtree.display(indent + 1)
 
     def __repr__(self):
-        return ('DecisionFork(%r, %r, %r)'
-                % (self.attr, self.attrname, self.branches))
+        return ('DecisionFork({0!r}, {1!r}, {2!r})'
+                .format(self.attr, self.attrname, self.branches))
 
 
 class DecisionLeaf:
@@ -772,9 +772,9 @@ def test(predict, dataset, examples=None, verbose=0):
         if output == desired:
             right += 1
             if verbose >= 2:
-                print('   OK: got %s for %s' % (desired, example))
+                print('   OK: got {} for {}'.format(desired, example))
         elif verbose:
-            print('WRONG: got %s, expected %s for %s' % (
+            print('WRONG: got {}, expected {} for {}'.format(
                 output, desired, example))
     return 1 - (right / len(examples))
 
diff --git a/nlp.py b/nlp.py
index 7273b98da..e10c3c044 100644
--- a/nlp.py
+++ b/nlp.py
@@ -52,7 +52,7 @@ def isa(self, word, cat):
         return cat in self.categories[word]
 
     def __repr__(self):
-        return '<Grammar %s>' % self.name
+        return '<Grammar {}>'.format(self.name)
 
 E0 = Grammar('E0',
              Rules(  # Grammar for E_0 [Figure 22.4]
@@ -158,7 +158,7 @@ def add_edge(self, edge):
         if edge not in self.chart[end]:
             self.chart[end].append(edge)
             if self.trace:
-                print('Chart: added %s' % (edge,))
+                print('Chart: added {}'.format(edge))
             if not expects:
                 self.extender(edge)
             else:
diff --git a/probability.py b/probability.py
index ed3aa5243..c0201595f 100644
--- a/probability.py
+++ b/probability.py
@@ -80,7 +80,7 @@ def show_approx(self, numfmt='%.3g'):
                           for (v, p) in sorted(self.prob.items())])
 
     def __repr__(self):
-        return "P(%s)" % self.varname
+        return "P({})".format(self.varname)
 
 
 class JointProbDist(ProbDist):
@@ -117,7 +117,7 @@ def values(self, var):
         return self.vals[var]
 
     def __repr__(self):
-        return "P(%s)" % self.variables
+        return "P({})".format(self.variables)
 
 
 def event_values(event, variables):
@@ -192,14 +192,14 @@ def variable_node(self, var):
         for n in self.nodes:
             if n.variable == var:
                 return n
-        raise Exception("No such variable: %s" % var)
+        raise Exception("No such variable: {}".format(var))
 
     def variable_values(self, var):
         "Return the domain of var."
         return [True, False]
 
     def __repr__(self):
-        return 'BayesNet(%r)' % self.nodes
+        return 'BayesNet({0!r})'.format(self.nodes)
 
 
 class BayesNode:
diff --git a/search.py b/search.py
index 12a723662..fb4e523c0 100644
--- a/search.py
+++ b/search.py
@@ -96,7 +96,7 @@ def __init__(self, state, parent=None, action=None, path_cost=0):
             self.depth = parent.depth + 1
 
     def __repr__(self):
-        return "<Node %s>" % (self.state,)
+        return "<Node {}>".format(self.state)
 
     def __lt__(self, node):
         return self.state < node.state
@@ -1132,7 +1132,7 @@ def __getattr__(self, attr):
         return getattr(self.problem, attr)
 
     def __repr__(self):
-        return '<%4d/%4d/%4d/%s>' % (self.succs, self.goal_tests,
+        return '<{:4d}/{:4d}/{:4d}/{}>'.format(self.succs, self.goal_tests,
                                      self.states, str(self.found)[:4])
 
 

<!DOCTYPE html PUBLIC '-//W3C//DTD XHTML 1.0 Transitional//EN' 'http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd'>
<html xmlns='http://www.w3.org/1999/xhtml'>
<head>
<title>pFad - Phonifier reborn</title>
<meta http-equiv='Content-Type' content='text/html; charset=utf-8' />
</head>
<body>
<h1>Pfad - The Proxy pFad of &#169; 2024 Garber Painting. All rights reserved.</h1>


<!-- Disclaimer -->
<p>Note: This service is not intended for secure transactions such as banking, social media, email, or purchasing. Use at your own risk. We assume no liability whatsoever for broken pages.</p>
<br>
<p>Alternative Proxies:</p><p><a href="http://rainy.clevelandohioweatherforecast.com/php-proxy/index.php?q=https://patch-diff.githubusercontent.com/raw/aimacode/aima-python/pull/292.diff" target="_blank">Alternative Proxy</a></p><p><a href="http://rainy.clevelandohioweatherforecast.com/pFad/index.php?u=https://patch-diff.githubusercontent.com/raw/aimacode/aima-python/pull/292.diff" target="_blank">pFad Proxy</a></p><p><a href="http://rainy.clevelandohioweatherforecast.com/pFad/v3index.php?u=https://patch-diff.githubusercontent.com/raw/aimacode/aima-python/pull/292.diff" target="_blank">pFad v3 Proxy</a></p><p><a href="http://rainy.clevelandohioweatherforecast.com/pFad/v4index.php?u=https://patch-diff.githubusercontent.com/raw/aimacode/aima-python/pull/292.diff" target="_blank">pFad v4 Proxy</a></p></body>
</html>