gitignore_clean.py: refactoring

1. Import only function `glob` from `glob` module
2. Extract `GITIGNORE_PATH` and functions `read_gitignore`, `delete`,
   `extend_wildcards`
3. Wrap runtime code in `if __name__ == "__main__"`

src/gitignore_clean.py

@@ -1,31 +1,53 @@
 #!/usr/bin/python3
 
 import os
-import glob
+from glob import glob
 from shutil import rmtree
 
+GITIGNORE_PATH = "./.gitignore"
 DRY_RUN = False
 
 
+def read_gitignore():
+    res = ""
+    with open(GITIGNORE_PATH, "r", encoding="utf-8-sig") as gitignore_file:
+        res = gitignore_file.read().splitlines()
+    return res
+
+
+def delete(file_path: str):
+    is_dir = os.path.isdir(file_path)
+    is_file = os.path.isfile(file_path)
+
+    if not (is_dir or is_file):
+        return
+
+    display_file_path = os.path.abspath(file_path)
+    if is_dir:
+        print("Removing directory", display_file_path)
+    elif is_file:
+        print("Removing file", display_file_path)
+
+    if DRY_RUN:
+        return
+
+    if os.path.isdir(file_path):
+        rmtree(file_path, ignore_errors=True)
+    elif os.path.isfile(file_path):
+        os.remove(file_path)
+
+
+def extend_wildcards(patterns: list):
+    res = []
+    for pattern in patterns:
+        res.extend(glob(pattern, recursive=True))
+    return res
+
+
 def clean_gitignored_files():
-    gitignore_patterns = []
-    with open(".gitignore", "r", encoding="utf-8-sig") as gitignore_file:
-        gitignore_patterns = gitignore_file.read().splitlines()
-
-    ignored_files = []
-    for pattern in gitignore_patterns:
-        ignored_files.extend(glob.glob(pattern, recursive=True))
-
-    for file_path in ignored_files:
-        display_file_path = os.path.abspath(file_path)
-        if os.path.isdir(file_path):
-            print("Removing directory", display_file_path)
-            if not DRY_RUN:
-                rmtree(file_path, ignore_errors=True)
-        else:
-            print("Removing file", display_file_path)
-            if not DRY_RUN:
-                os.remove(file_path)
+    for file_path in extend_wildcards(read_gitignore()):
+        delete(file_path)
 
 
-clean_gitignored_files()
+if __name__ == "__main__":
+    clean_gitignored_files()