shorten long entries in the Value column

inspector.py

@@ -79,7 +79,7 @@ class VariableInspector(object, metaclass=Singleton):
 
 
 def format_line(k, v):
-    return LINE.format(k, typename(v), size(v), v)
+    return LINE.format(k, typename(v), size(v), format_value(v))
 
 def sorted_naturally(iterable, reverse=False):
     natural = lambda item: [int(c) if c.isdigit() else c.casefold() for c in RE_DIGITS.split(str(item))]
@@ -100,6 +100,18 @@ def size(obj):
         except TypeError:
             return ""
 
+def format_value(obj): #TODO: make magic numbers configurable
+    res = str(obj)
+    # try if separate lines can be used to shorten
+    splitted = res.split("\n")
+    if len(splitted) > 4:
+        res = splitted[0] + " ... " + splitted[-1]
+    # if still too long (or no lines), cut the middle part
+    if len(res) < 120:
+        return res
+    res = res[:50] + " ... " + res[-50:]
+    return res
+
 
 
 inspector = VariableInspector()