diff --git a/rclpy/rclpy/duration.py b/rclpy/rclpy/duration.py
index c59fc559e..4fde06f38 100644
--- a/rclpy/rclpy/duration.py
+++ b/rclpy/rclpy/duration.py
@@ -34,6 +34,11 @@ def nanoseconds(self):
     def __repr__(self):
         return 'Duration(nanoseconds={0})'.format(self.nanoseconds)
 
+    def __str__(self):
+        if self == Infinite:
+            return 'Infinite'
+        return f'{self.nanoseconds} nanoseconds'
+
     def __eq__(self, other):
         if isinstance(other, Duration):
             return self.nanoseconds == other.nanoseconds
@@ -79,3 +84,7 @@ def from_msg(cls, msg):
 
     def get_c_duration(self):
         return self._duration_handle
+
+
+# Constant representing an infinite amount of time.
+Infinite = Duration(nanoseconds=_rclpy.RMW_DURATION_INFINITE)
diff --git a/rclpy/rclpy/topic_endpoint_info.py b/rclpy/rclpy/topic_endpoint_info.py
index be4ceb773..7569a926d 100644
--- a/rclpy/rclpy/topic_endpoint_info.py
+++ b/rclpy/rclpy/topic_endpoint_info.py
@@ -158,17 +158,18 @@ def __eq__(self, other):
             for slot in self.__slots__)
 
     def __str__(self):
-        result = 'Node name: %s\n' % self.node_name
-        result += 'Node namespace: %s\n' % self.node_namespace
-        result += 'Topic type: %s\n' % self.topic_type
-        result += 'Endpoint type: %s\n' % self.endpoint_type.name
-        result += 'GID: %s\n' % '.'.join(format(x, '02x') for x in self.endpoint_gid)
-        result += 'QoS profile:\n'
-        result += '  Reliability: %s\n' % self.qos_profile.reliability.name
-        result += '  Durability: %s\n' % self.qos_profile.durability.name
-        result += '  Lifespan: %d nanoseconds\n' % self.qos_profile.lifespan.nanoseconds
-        result += '  Deadline: %d nanoseconds\n' % self.qos_profile.deadline.nanoseconds
-        result += '  Liveliness: %s\n' % self.qos_profile.liveliness.name
-        result += '  Liveliness lease duration: %d nanoseconds' % \
-            self.qos_profile.liveliness_lease_duration.nanoseconds
-        return result
+        gid = '.'.join(format(x, '02x') for x in self.endpoint_gid)
+        return '\n'.join([
+            f'Node name: {self.node_name}',
+            f'Node namespace: {self.node_namespace}',
+            f'Topic type: {self.topic_type}',
+            f'Endpoint type: {self.endpoint_type.name}',
+            f'GID: {gid}',
+            'QoS profile:',
+            f'  Reliability: {self.qos_profile.reliability.name}',
+            f'  Durability: {self.qos_profile.durability.name}',
+            f'  Lifespan: {self.qos_profile.lifespan}',
+            f'  Deadline: {self.qos_profile.deadline}',
+            f'  Liveliness: {self.qos_profile.liveliness.name}',
+            f'  Liveliness lease duration: {self.qos_profile.liveliness_lease_duration}',
+        ])
diff --git a/rclpy/src/rclpy/_rclpy_pybind11.cpp b/rclpy/src/rclpy/_rclpy_pybind11.cpp
index 2fbacb1ae..01df8143c 100644
--- a/rclpy/src/rclpy/_rclpy_pybind11.cpp
+++ b/rclpy/src/rclpy/_rclpy_pybind11.cpp
@@ -58,6 +58,7 @@ PYBIND11_MODULE(_rclpy_pybind11, m) {
   .value("STEADY_TIME", RCL_STEADY_TIME);
 
   m.attr("RCL_DEFAULT_DOMAIN_ID") = py::int_(RCL_DEFAULT_DOMAIN_ID);
+  m.attr("RMW_DURATION_INFINITE") = py::int_(rmw_time_total_nsec(RMW_DURATION_INFINITE));
 
   py::enum_<rcl_clock_change_t>(m, "ClockChange")
   .value(
diff --git a/rclpy/test/test_time.py b/rclpy/test/test_time.py
index d00178107..c89aa0a4b 100644
--- a/rclpy/test/test_time.py
+++ b/rclpy/test/test_time.py
@@ -16,6 +16,7 @@
 
 from rclpy.clock import ClockType
 from rclpy.duration import Duration
+from rclpy.duration import Infinite
 from rclpy.time import Time
 
 from test_msgs.msg import Builtins
@@ -228,3 +229,7 @@ def test_seconds_nanoseconds(self):
         assert (1, int(5e8)) == Time(seconds=1, nanoseconds=5e8).seconds_nanoseconds()
         assert (1, int(5e8)) == Time(seconds=0, nanoseconds=15e8).seconds_nanoseconds()
         assert (0, 0) == Time().seconds_nanoseconds()
+
+    def test_infinite_duration(self):
+        duration = Infinite
+        assert str(duration) == 'Infinite'