def generateGradeJson():
try:
grade_dict={
"grade":[]
}
grade_list=Grade.get_grades()
for i in grade_list:
grade_dict["grade"].append(i)
with open(__StaticDir__+"grade.json",'w') as f:
f.write(json.dumps(grade_dict))#把json格式的内容写入文件
except StandardError,e:
#print e
raise