ValueError: invalid literal for int(): Screw plugg (91_10 -> untitled) in python

Question

hi,

i have

form = self.request.form 
partintid = int(form['item_01bom']) # value is 'Screw plugg (91_10 -> untitled)' 
print partintid

i want to convert 'Screw plugg (91_10 -> untitled)' to int.

but i get ValueError: invalid literal for int(): Screw plugg (91_10 -> untitled).