From b5a314588c7b954dc7aad9665e9c86cf2b2c7753 Mon Sep 17 00:00:00 2001
From: Dan Howe <d.howe@wrl.unsw.edu.au>
Date: Thu, 19 Apr 2018 07:14:41 +1000
Subject: [PATCH] Raise error if layer is empty

---
 dxf_to_csv/dxf_to_csv.py | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/dxf_to_csv/dxf_to_csv.py b/dxf_to_csv/dxf_to_csv.py
index cfd77e5..978c158 100644
--- a/dxf_to_csv/dxf_to_csv.py
+++ b/dxf_to_csv/dxf_to_csv.py
@@ -24,10 +24,6 @@ Convert specific layer:
 
 """
 
-__author__ = "D. Howe"
-__version__ = "0.2.0"
-__email__ = "d.howe@wrl.unsw.edu.au"
-
 import os
 import sys
 import numpy as np
@@ -96,6 +92,13 @@ def convert(dxf_name, layer_name):
     # Add to dataframe
     points = pd.DataFrame(data)
 
+    # Ensure dataframe is not empty
+    if points.shape[0] == 0:
+        if layer_name:
+            raise ValueError('No objects found on layer {}'.format(layer_name))
+        else:
+            raise ValueError('No objects found.')
+
     # Check if there are z coordinates
     if 'z' not in points.columns:
         points['z'] = np.nan