don't crash on empty subpaths

1 files changed, 4 insertions, 1 deletions

diff --git a/lib/elements/element.py b/lib/elements/element.py
index 300136dd..42f6c470 100644
--- a/lib/elements/element.py
+++ b/lib/elements/element.py
@@ -29,6 +29,10 @@ class Patch:
         else:
             raise TypeError("Patch can only be added to another Patch")
 
+    def __len__(self):
+        # This method allows `len(patch)` and `if patch:
+        return len(self.stitches)
+
     def add_stitch(self, stitch):
         self.stitches.append(stitch)
 
@@ -36,7 +40,6 @@ class Patch:
         return Patch(self.color, self.stitches[::-1])
 
 
-
 class Param(object):
     def __init__(self, name, description, unit=None, values=[], type=None, group=None, inverse=False, default=None, tooltip=None, sort_index=0):
         self.name = name