reorganise directories

upd chapter_01/binary.py

chapter_07/README.md

@@ -0,0 +1,8 @@
+# BFS DFS on rooted tree (connected acyclic graph)
+
+The BFS example uses a queue which results in a breadth first search. When a directory is found its contents are appended to the queue to be processed later
+
+The DFS example uses the call stack which results in a depth first search. When a directory is found it is recursively passed to files_with_extension to be processed immediately.
+
+Note. DFS cannot be used to find the shortest path. In the mango seller example, a DFS search may have found a second or third degree
+seller before a first. However, DFS may be used to find the topological sort.

chapter_07/bfs_dirtrav.py

@@ -0,0 +1,31 @@
+import logging
+from collections import deque
+from pathlib import Path
+
+logging.basicConfig(level=logging.DEBUG)
+logger = logging.getLogger(__name__)
+
+EXT = ".rb"
+
+scripts_path = Path.home() / "scripts"
+
+
+def files_with_extension(start_directory):
+    queue = deque()
+    queue.append(start_directory)
+
+    while queue:
+        items = queue.popleft()
+
+        for item in items.glob("*"):
+            # if item is a file and has extension EXT then print
+            if item.is_file():
+                if item.suffix == EXT:
+                    print(item)
+
+            # otherwise append directory to the queue
+            else:
+                queue.append(item)
+
+
+files_with_extension(scripts_path)

chapter_07/dfs_dirtrav.py

@@ -0,0 +1,24 @@
+import logging
+from pathlib import Path
+
+logging.basicConfig(level=logging.DEBUG)
+logger = logging.getLogger(__name__)
+
+EXT = ".rb"
+
+scripts_path = Path.home() / "scripts"
+
+
+def files_with_extension(directory):
+    for item in directory.glob("*"):
+        # if item is a file and has extension EXT then print
+        if item.is_file():
+            if item.suffix == EXT:
+                print(item)
+
+        # otherwise pass directory to recursive call
+        else:
+            files_with_extension(item)
+
+
+files_with_extension(scripts_path)