Hello, any ideas why this does not work? >>> def add(key, num): ... a[key] += num ... >>> a={} >>> a["007-12"] = 22 if not a.has_key("007-12") else add("007-12",22) >>> a {'007-12': 22} # OK here, this is what I want >>> a["007-12"] = 22 if not a.has_key("007-12") else add("007-12",22) >>> a {'007-12': None} # why does this became None? Thanks