finish an example file for netlist to graph using graph_tool

src/kfactory/utils/netlist_to_graph.py

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+import kfactory as kf
+from pathlib import Path
+import os
+from graph_tool.all import *  # <- You need to install graph_tool through "conda install -c conda-forge graph-tool"
+
+
+def save_netlist(nl: kf.kdb.Netlist, filename: str):
+    file_name = Path.cwd() / "netlist" / filename
+    if not os.path.exists("netlist"):
+        os.makedirs("netlist")
+    with open(file_name, "w") as f:
+        f.write(nl.to_s())
+
+
+def parse_stored_netlist(filename: str):
+    """
+    Args:
+        A netlist txt file stored by save_netlist function
+    Return:
+        A list of connected nodes and their connection label. For example,
+        [('0', '1', '0_o2-1_o1'), ('1', '2', '1_o2-2_o1'), ('2', '3', '2_o2-3_o1')]
+        represent a graph with three edges:
+            Edge 1: Connection between vertex 0 and vertex 1, and the detailed connection information is
+                    '0_o2-1_o1' meaning that the o2 port of vertex 0 is connected to o1 port of vertex 1.
+            Edge 2: Connection between vertex 1 and vertex 2, and the detailed connection information is
+                    '1_o2-2_o1' meaning that the o2 port of vertex 1 is connected to o1 port of vertex 2.
+            Edge 3: Connection between vertex 2 and vertex 3, and the detailed connection information is
+                    '2_o2-3_o1' meaning that the o2 port of vertex 2 is connected to o1 port of vertex 3.
+        This list can be sent to Graph() function from graph_tool directly.
+    """
+    port_connection = []
+    device_label_map = {}
+    file_name = Path.cwd() / "netlist" / filename
+    if not os.path.exists("netlist"):
+        os.makedirs("netlist")
+
+    # parse netlist txt file to generate port_connection and device name map
+    with open(file_name, "r") as f:
+        for line in f:
+            if len(line.split(" ")) > 1:
+                if line.split(" ")[2] == "subcircuit":
+                    port_connection.append(line.split(" ")[-1])
+                    device_label_map[
+                        line.split(" ")[-2].split("_")[0][1:]
+                    ] = line.split(" ")[-2]
+    # further extract connection information from port_connection
+    input_in_net = []
+    output_in_net = []
+    for pc in port_connection:
+        if pc.split(",")[0].split("=")[-1].startswith("o"):
+            input_in_net.append(pc.split(",")[0].split("=")[-1])
+        else:
+            input_in_net.append(pc.split(",")[0].split("=")[-1][1:-1])
+        if pc.split(",")[1].split("=")[-1][0:-3].startswith("o"):
+            output_in_net.append(pc.split(",")[1].split("=")[-1][0:-3])
+        else:
+            output_in_net.append(pc.split(",")[1].split("=")[-1][1:-4])
+
+    # construct a list of connected
+    input_for_graph = []
+    for i in range(len(input_in_net)):
+        if len(input_in_net[i].split("-")) == 2:
+            input_for_graph.append(
+                (
+                    (input_in_net[i].split("-")[0].split("_")[0]),
+                    (input_in_net[i].split("-")[1].split("_")[0]),
+                    input_in_net[i],
+                )
+            )
+
+    return input_for_graph
+
+
+def plot_netlist(
+    input_for_graph: list, port_loc: dict = None, save_graph: str = "netlist_graph.pdf"
+):
+
+    file_name = Path.cwd() / "netlist" / save_graph
+    if not os.path.exists("netlist"):
+        os.makedirs("netlist")
+    file_name = str(file_name)
+    # Creating a graph
+    g = Graph(
+        input_for_graph, hashed=True, eprops=[("connection", "string")], directed=False
+    )  # undirected graph
+
+    # adding vertex property (provide information for vertices' location)
+    pos = g.new_vertex_property("vector<double>")
+    if port_loc is not None:
+        for v in g.vertices():
+            pos[v] = port_loc[v]
+        graph_draw(
+            g,
+            vertex_text=g.vertex_index,
+            pos=pos,
+            edge_text=g.ep.connection,
+            vertex_font_size=16,
+            edge_font_size=12,
+            output_size=(300, 300),
+            output=file_name,
+        )
+    else:
+        graph_draw(
+            g,
+            vertex_text=g.vertex_index,
+            edge_text=g.ep.connection,
+            edge_font_size=12,
+            output=file_name,
+        )
+
+
+if __name__ == "__main__":
+
+    c = kf.KCell()
+
+    b = kf.cells.circular.bend_circular(width=1, radius=10, layer=kf.kcl.layer(1, 0))
+    s = kf.cells.waveguide.waveguide(width=1, length=20, layer=kf.kcl.layer(1, 0))
+
+    b1 = c << b
+    b2 = c << b
+    b2.connect("o1", b1, "o2")
+    b3 = c << b
+    b3.connect("o1", b2, "o2")
+    s1 = c << s
+    s1.connect("o1", b3, "o2")
+    c.add_port(b1.ports["o1"])
+    c.add_port(s1.ports["o2"])
+
+    nl = c.netlist()
+    # save a netlist to txt file
+    save_netlist(nl, "temp.txt")
+
+    # Define the location of vertex in your graph -> This is not a necessary step.
+    # But if you do so, you can better visualize your graph.
+    dev_list = [b1, b2, b3, s1]
+    port_loc = {}
+    for i, d in enumerate(dev_list):
+        _x = d.ports["o2"].x
+        _y = d.ports["o2"].y
+        port_loc[i] = (_x, -_y)
+
+    input_graph = parse_stored_netlist(filename="temp.txt")
+
+    plot_netlist(input_for_graph=input_graph, port_loc=port_loc, save_graph="temp.pdf")