bug fixes (#118)

src/update.py

@@ -3,11 +3,17 @@
 import subprocess
 import config
 
+def safe_literal_eval(node):
+    try:
+        return ast.literal_eval(node)
+    except ValueError:
+        return None
+
 def get_assignments(filename):
     with open(filename) as f:
         tree = ast.parse(f.read(), filename)
 
-    assignments = {node.targets[0].id: ast.literal_eval(node.value) for node in ast.walk(tree) if isinstance(node, ast.Assign)}
+    assignments = {node.targets[0].id: safe_literal_eval(node.value) for node in ast.walk(tree) if isinstance(node, ast.Assign)}
     return assignments