diff --git a/samples/python/reactors/mix1.py b/samples/python/reactors/mix1.py
index 9cb34feb7..9cc2ad97e 100644
--- a/samples/python/reactors/mix1.py
+++ b/samples/python/reactors/mix1.py
@@ -16,19 +16,23 @@ contain all species that might be present in any upstream reactor.
 Compare this approach for the transient problem to the method used for the
 steady-state problem in :doc:`mixing.py <../thermo/mixing>`.
 
-Requires: cantera >= 2.5.0
+Requires: cantera >= 3.1.0, graphviz
 
 .. tags:: Python, thermodynamics, reactor network, mixture
 """
 
 import cantera as ct
 
+# %%
+# Set up the reactor network
+# --------------------------
+#
 # Use air for stream a.
 gas_a = ct.Solution('air.yaml')
 gas_a.TPX = 300.0, ct.one_atm, 'O2:0.21, N2:0.78, AR:0.01'
 rho_a = gas_a.density
 
-
+# %%
 # Use GRI-Mech 3.0 for stream b (methane) and for the mixer. If it is desired
 # to have a pure mixer, with no chemistry, use instead a reaction mechanism
 # for gas_b that has no reactions.
@@ -36,36 +40,48 @@ gas_b = ct.Solution('gri30.yaml')
 gas_b.TPX = 300.0, ct.one_atm, 'CH4:1'
 rho_b = gas_b.density
 
+# %%
 # Create reservoirs for the two inlet streams and for the outlet stream.  The
-# upsteam reservoirs could be replaced by reactors, which might themselves be
+# upstream reservoirs could be replaced by reactors, which might themselves be
 # connected to reactors further upstream. The outlet reservoir could be
 # replaced with a reactor with no outlet, if it is desired to integrate the
 # composition leaving the mixer in time, or by an arbitrary network of
 # downstream reactors.
-res_a = ct.Reservoir(gas_a)
-res_b = ct.Reservoir(gas_b)
-downstream = ct.Reservoir(gas_b)
+res_a = ct.Reservoir(gas_a, name='air')
+res_b = ct.Reservoir(gas_b, name='fuel')
+downstream = ct.Reservoir(gas_b, name='outlet')
 
+# %%
 # Create a reactor for the mixer. A reactor is required instead of a
 # reservoir, since the state will change with time if the inlet mass flow
 # rates change or if there is chemistry occurring.
 gas_b.TPX = 300.0, ct.one_atm, 'O2:0.21, N2:0.78, AR:0.01'
-mixer = ct.IdealGasReactor(gas_b)
+mixer = ct.IdealGasReactor(gas_b, name='mixer')
 
-# create two mass flow controllers connecting the upstream reservoirs to the
+# %%
+# Create two mass flow controllers connecting the upstream reservoirs to the
 # mixer, and set their mass flow rates to values corresponding to
 # stoichiometric combustion.
 mfc1 = ct.MassFlowController(res_a, mixer, mdot=rho_a*2.5/0.21)
 mfc2 = ct.MassFlowController(res_b, mixer, mdot=rho_b*1.0)
 
-# connect the mixer to the downstream reservoir with a valve.
+# %%
+# Connect the mixer to the downstream reservoir with a valve.
 outlet = ct.Valve(mixer, downstream, K=10.0)
 
 sim = ct.ReactorNet([mixer])
 
-# Since the mixer is a reactor, we need to integrate in time to reach steady
-# state
+# %%
+# Get the mixed state
+# -------------------
+#
+# Since the mixer is a reactor, we need to integrate in time to reach steady state.
 sim.advance_to_steady_state()
 
 # view the state of the gas in the mixer
 print(mixer.thermo.report())
+
+# %%
+# Show the network structure
+# --------------------------
+diagram = sim.draw(print_state=True, species="X")