字典习题:已知字典：ainfo = {‘ab‘:‘liming‘,‘ac‘:20}完成下面的操作1 使用2个方法，输出的结果：ainfo = {‘ab‘:‘liming‘,‘ac‘:20,‘sex‘:‘man‘,‘age‘:20}2 输出结果：[‘ab‘,‘ac‘]3 输出结果：[‘liming‘,20]4 通过2个方法返回键名ab对应的值。5 通过2个方法删除键名ac对应的值。ainfo = {‘ab‘:‘liming‘,‘ac‘:20}binfo = {‘ab‘:‘liming‘,‘ac‘:20}ainfo[‘sex‘] = ‘man‘ainfo[‘age‘] = 20print ainfoprint binfo.keys()print binfo.values()print ainfo[‘ab‘]del ainfo[‘ac‘]print ainfo