Raise error if layer is empty

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