Geonames 500 example trie, build status, trie graph

README.md

@@ -1,6 +1,10 @@
+[![Build Status](https://drone.friedl.net/api/badges/incubator/bytetrie/status.svg)](https://drone.friedl.net/incubator/bytetrie)
+
 # Bytetrie
 A fast, dependency-free, self-compressing trie with radix 256 in pure python.
 
+![](trie.png)
+
 Bytetrie allows fast prefix search in a large corpus of keys. Each key can be
 associated with arbitrary data. It features fast lookup times at the cost of
 expensive insertion. A Bytetrie is best used if it can be pre-filled with data.

examples/gen.sh

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+#!/bin/sh
+
+xwim cities500.tar.gz
+mv cities500/cities500.txt .
+rmdir cities500
+python geonames.py
+twopi -Tpng geo_dot.dot -o geo_dot_twopi.png -Groot=root -x

examples/geonames.py

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+import csv
+from bytetrie import ByteTrie
+
+def load_geonames():
+    t = ByteTrie(multi_value=True)
+    with open("cities500.txt", "r") as f:
+        reader = csv.reader(f, delimiter='\t')
+        for i, row in enumerate(reader):
+            try:
+                t.insert(row[1].encode("utf-8"), row[17])
+            except Exception:
+                print(f"Error in row {i}")
+                print(f"Label: '{row[1]}'")
+                print(f"Type: {type(row[1])}")
+                raise
+    return t
+
+def insert(trie):
+    """ Shall only be used to insert strings """
+    t = trie
+    def _insert(*vals):
+        for val in vals:
+            t.insert(val.encode('utf-8'), val)
+    return _insert
+
+def load_simple_trie():
+    t = ByteTrie()
+    ins = insert(t)
+    ins("A")
+    ins("AA", "AB")
+    ins("ABCDE")
+    ins("AACDEF", "AACDEGG", "AACDEH")
+    return t
+
+# This uses internal representations which are not supposed to
+# be used as public API and are subject to change!
+from bytetrie.bytetrie import ByteTrie, Node, Root, Child, Terminal
+def geonames_to_dot(t: ByteTrie):
+    dot_buffer = str()
+    dot_buffer += """strict digraph {
+    graph [
+        bgcolor="transparent"
+    ];
+
+    edge [
+        arrowhead="none",
+        penwidth="0.05",
+    ];
+
+    node [
+        label="",
+        sep="2"
+    ];
+
+    root [shape="circle", width="0.4"]
+    """
+
+    hue_inc = 1/len(t.root.children)
+    hue = 0
+
+    for child in t.root.children:
+        dot_buffer += _geonames_node_to_dot(t.root, child, 1, hue)
+        hue += hue_inc
+
+    dot_buffer += "}"
+    return dot_buffer
+
+def _geonames_node_to_dot(p: Node, n: Child, depth, hue):
+    db = f'{p.dot_id()} -> {n.dot_id()} [color="{hue},{depth*0.1},85"]\n'
+    db += f'{n.dot_id()} [color="{hue},{depth*0.1},50", shape="circle", width="0.1"]\n'
+
+    for child in n.children:
+        db += _geonames_node_to_dot(n, child, depth+1, hue)
+
+    return db
+
+
+if __name__ == "__main__":
+    t = load_geonames()
+    s = geonames_to_dot(t)
+    with open("geo_dot.dot", "w") as f:
+        f.write(s)