Python: basic, package install, error handler for begining

Signed-off-by: Václav Valíček <valicek1994@gmail.com>

repo_cloner/lib/dir_not_found_error.py

@@ -0,0 +1,15 @@
+from pathlib import PosixPath
+
+
+class DirNotFoundError(OSError):
+
+	def __str__(self):
+		if len(self.args) >= 1:
+			path: str = ""
+			if isinstance(self.args[0], PosixPath):
+				path = str(PosixPath(self.args[0]))
+			else:
+				path = str(self.args[0])
+			return f"Directory does not exist / is not a dir: {path}"
+		else:
+			return super.__str__(self)