用Python完成根据日期计算是星期几?

import datetime

def week(year,month,day):

someday=dayetime.date(year,month,day)

result={

"0":"星期日",

"1":"星期一",

"2":"星期二",

"3":"星期三",

"4":"星期四",

"5":"星期五",

"6":星期六""

}

return result.get(someday.strftime('%w'))