打印三级菜单，打印文件最后一行

1、用户交互，显示省市县三级联动的选择

dic = {

    "河北": {

        "石家庄": ["鹿泉", "藁城", "元氏"],

        "邯郸": ["永年", "涉县", "磁县"],

    }

    "河南": {

        ...

    }

    "山西": {

        ...

    }

 

}

#!/usr/bin/env python
# coding:utf-8
dic = {
    "河北": {
        "石家庄": ["鹿泉", "藁城", "元氏"],
        "邯郸": ["永年", "涉县", "磁县"],
    },
    "河南": {
        ...
    },
    "山西": {
        ...
    }

}
print(type(dic))
def  threedic(dict):
    while True:
        for i  in dict:             #河北  河南   山西              石家庄邯郸
            print(i)
        key=input("》》》： ").strip()   # 河北
        if key == 'b' or key == 'q':
            return key
        if type(dict) == list:
            continue
        else :
            if  key in dict.keys()  and dict[key]  :
                ret = threedic(dict[key])         #  河北的  值   石家庄   邯郸
                if ret == 'q':
                    return ret
                continue
            elif  not dict.get(key)  or  not dict[key] :
                continue

threedic(dic)

 

2.打印出一个文件的最后一行

def last():
    f=open('test.py','rb')
    offs=-10
    while True :
        res=[]
        f.seek(offs,2)
        a=f.readlines()
        for i  in  a :
            res.append(i)
            if len(res)>1 :
                print("文件的最后一行是:  %s" %((res[-1]).decode('utf-8')))
                exit()
            else :
                offs*=2
lsat()

 3、统计字符串中大小写字母，数字出现的个数，并以字典方式打印出来

def  tongji(x):
    a=b=c=0
    for  i  in x:
        if   i>='a'  and i<= 'z':
           a+=1
        if  i>='A'  and  i <='Z' :
            b+=1
        if  i>='0' and i<='9':
            c+=1
    list1=['大写字母','小写字母','数字']
    list2=[a,b,c]
    dict(zip(list1,list2))
    print (dict(zip(list1,list2)))
tongji('A12345asdasd')