Merge pull request e2nIEE#1529 from dlohmeier/feature/subnet_selection

slight changes to subnet selection (small performance improvement)

pandapower/test/api/test_toolbox.py

@@ -523,6 +523,9 @@ def test_select_subnet():
     assert pp.dataframes_equal(net.line, same_net.line)
     assert pp.dataframes_equal(net.load, same_net.load)
     assert pp.dataframes_equal(net.ext_grid, same_net.ext_grid)
+    same_net2 = pp.select_subnet(net, net.bus.index, include_results=True,
+                                 keep_everything_else=True)
+    assert pp.nets_equal(net, same_net2)
 
     # Remove everything
     empty = pp.select_subnet(net, set())
@@ -546,6 +549,10 @@ def test_select_subnet():
     line_switch_buses = set(net.switch[net.switch.et == 'l'].bus)
     subnet = pp.select_subnet(net, from_bus | to_bus | line_switch_buses)
     assert net.switch[net.switch.et == 'l'].index.isin(subnet.switch.index).all()
+    ls = net.switch.loc[net.switch.et == "l"]
+    subnet = pp.select_subnet(net, list(ls.bus.values)[::2], include_switch_buses=True)
+    assert net.switch[net.switch.et == 'l'].index.isin(subnet.switch.index).all()
+    assert net.switch[net.switch.et == 'l'].bus.isin(subnet.bus.index).all()
 
     # This network has switches of type 'b'
     net2 = nw.create_cigre_network_lv()

pandapower/toolbox.py

@@ -1585,14 +1585,14 @@ def select_subnet(net, buses, include_switch_buses=False, include_results=False,
         # we add both buses of a connected line, the one selected is not switch.bus
 
         # for all line switches
-        for _, s in net["switch"].query("et=='l'").iterrows():
+        for s in net["switch"].query("et=='l'").itertuples():
             # get from/to-bus of the connected line
-            fb = net["line"]["from_bus"].at[s["element"]]
-            tb = net["line"]["to_bus"].at[s["element"]]
+            fb = net["line"]["from_bus"].at[s.element]
+            tb = net["line"]["to_bus"].at[s.element]
             # if one bus of the line is selected and its not the switch-bus, add the other bus
-            if fb in buses and s["bus"] != fb:
+            if fb in buses and s.bus != fb:
                 buses.add(tb)
-            if tb in buses and s["bus"] != tb:
+            if tb in buses and s.bus != tb:
                 buses.add(fb)
 
     if keep_everything_else:
@@ -1603,12 +1603,12 @@ def select_subnet(net, buses, include_switch_buses=False, include_results=False,
         p2 = create_empty_network(add_stdtypes=False)
         p2["std_types"] = copy.deepcopy(net["std_types"])
 
-    net_parameters = ["name", "f_hz"]
-    for net_parameter in net_parameters:
-        if net_parameter in net.keys():
-            p2[net_parameter] = net[net_parameter]
+        net_parameters = ["name", "f_hz"]
+        for net_parameter in net_parameters:
+            if net_parameter in net.keys():
+                p2[net_parameter] = net[net_parameter]
 
-    p2.bus = net.bus.loc[buses]
+    p2.bus = net.bus.loc[list(buses)]
     for elm in pp_elements(bus=False, bus_elements=True, branch_elements=False,
                            other_elements=False, res_elements=False):
         p2[elm] = net[elm][net[elm].bus.isin(buses)]