fix relative file path error

main.py

@@ -40,7 +40,9 @@ def create_client(server_address: str = None, username: str = None, password: st
 def upload(_in: str, out: str, server_address: str = None, username: str = None, password: str = None, public_link: str = None, func=None):
     nc = create_client(server_address, username, password, public_link)
 
-    files_and_directories = glob.glob(os.path.join(_in, "**/*"), recursive=True)
+    search_path = os.path.join(_in, "**/*") if os.path.isdir(_in) else _in
+
+    files_and_directories = glob.glob(search_path, recursive=True)
     uploading_files = [f for f in files_and_directories if os.path.isfile(f)]
 
     already_uploaded = []
@@ -53,8 +55,10 @@ def upload(_in: str, out: str, server_address: str = None, username: str = None,
 
     for file_path in uploading_files:
         relative_file_path = os.path.relpath(file_path, _in)
-        remote_file_path = os.path.join(out, relative_file_path)
+        if relative_file_path == ".":
+            relative_file_path = ""
 
+        remote_file_path = os.path.join(out, relative_file_path)
         if remote_file_path not in already_uploaded_files:
             remote_dir_path = os.path.dirname(remote_file_path)
             create_remote_path_if_not_exists(remote_dir_path, nc)