From cdded22d2442f1c0f2fed1ef7c5e3d5861693dda Mon Sep 17 00:00:00 2001
From: Sten Linnarsson <sten.linnarsson@ki.se>
Date: Sat, 29 Sep 2018 00:45:51 -0700
Subject: [PATCH] prevent accidental file creation

---
 loompy/loompy.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/loompy/loompy.py b/loompy/loompy.py
index a4c483c..df7dd30 100755
--- a/loompy/loompy.py
+++ b/loompy/loompy.py
@@ -70,7 +70,8 @@ def __init__(self, filename: str, mode: str = 'r+', *, validate: bool = True, sp
 		Returns:
 			Nothing.
 		"""
-
+		if not os.path.exists(filename):
+			raise IOError(f"File '{filename}' not found")
 		# make sure a valid mode was passed
 		if mode != 'r+' and mode != 'r':
 			raise ValueError("Mode must be either 'r' or 'r+'")