Rewrite sole_subdir_lift to be more recursively useful.

sole_subdir_lift.py

@@ -1,9 +1,5 @@
-'''
-This program takes a directory and does the following: If that directory
-contains nothing but a single child directory, then the contents of that child
-will be moved to the parent, and the empty child will be deleted.
-'''
 import argparse
+import collections
 import os
 import shutil
 import sys
@@ -11,40 +7,63 @@ import sys
 from voussoirkit import passwordy
 from voussoirkit import pathclass
 from voussoirkit import pipeable
+from voussoirkit import spinal
+from voussoirkit import vlogging
 from voussoirkit import winglob
 
-def sole_lift(starting):
-    starting = pathclass.Path(starting)
-    children = starting.listdir()
-    if len(children) != 1:
-        return
+log = vlogging.getLogger(__name__, 'sole_subdir_lift')
+
+def main(argv):
+    argv = vlogging.set_level_by_argv(log, argv)
+
+def sole_lift_argparse(args):
+    starting = pathclass.Path(args.starting)
+    queue = collections.deque()
+    queue.extend(spinal.walk(starting, yield_files=False, yield_directories=True))
+    while len(queue) > 0:
+        directory = queue.popleft()
+
+        if not directory.exists:
+            log.debug('%s no longer exists.', directory)
+            continue
+
+        if directory not in starting:
+            log.debug('%s is outside of starting.', directory)
+            continue
+
+        children = directory.listdir()
+        child_count = len(children)
+        if child_count != 1:
+            log.debug('%s has %d children.', directory, child_count)
+            continue
 
         child = children[0]
 
         if not child.is_dir:
-        return
+            log.debug('%s contains a file, not a dir.', directory)
+            continue
 
-    temp_dir = starting.with_child(passwordy.urandom_hex(32))
+        log.info('Lifting contents of %s.', child.absolute_path)
+        # child is renamed to random hex so that the grandchildren we are about
+        # to lift don't have name conflicts with the child dir itself.
+        # Consider .\abc\abc where the grandchild can't be moved.
+        temp_dir = directory.with_child(passwordy.urandom_hex(32))
         os.rename(child.absolute_path, temp_dir.absolute_path)
         for grandchild in temp_dir.listdir():
-        shutil.move(grandchild.absolute_path, starting.absolute_path)
+            shutil.move(grandchild.absolute_path, directory.absolute_path)
 
         if temp_dir.listdir():
             raise Exception()
 
         os.rmdir(temp_dir.absolute_path)
-
-def sole_lift_argparse(args):
-    patterns = pipeable.input_many(args.patterns, skip_blank=True, strip=True)
-    directories = (pathclass.Path(d) for pattern in patterns for d in winglob.glob(pattern))
-    directories = (d for d in directories if d.is_dir)
-    for directory in directories:
-        sole_lift(directory)
+        queue.append(directory.parent)
 
 def main(argv):
+    argv = vlogging.set_level_by_argv(log, argv)
+
     parser = argparse.ArgumentParser(description=__doc__)
 
-    parser.add_argument('patterns', nargs='+', default='.')
+    parser.add_argument('starting', nargs='?', default='.')
     parser.set_defaults(func=sole_lift_argparse)
 
     args = parser.parse_args(argv)