Added .py file for support functions

extras.py

@@ -0,0 +1,11 @@
+import os
+
+def get_size(file_path, unit='bytes'):
+    file_size = os.path.getsize(file_path)
+    exponents_map = {'bytes': 0, 'kb': 1, 'mb': 2, 'gb': 3}
+    if unit not in exponents_map:
+        raise ValueError("Must select from \
+        ['bytes', 'kb', 'mb', 'gb']")
+    else:
+        size = file_size / 1024 ** exponents_map[unit]
+        return round(size, 1)