2.

def lst(input):

    lst2=[]

    count=0

    for i in range(0,len(input)):

        if i %2!=0:

            lst2.append(input[i])

    return lst2

a=lst((2,9,29,36,9))

print(a)

3.

def pd(input):

    if len(input)>5:

        return True

    else:

        return False

a=pd((5,5,6,9,7))

print(a)

4.

def a(input):

    if type(input)==list:

        if len(input)>2:

            return input[0],input[1]

    else:

        return ('请输入列表')

d=a(['小明','大明'])

print(d)

5.写函数，计算传入函数的字符串中, 数字、字母、空格 以及 其他内容的个数，并返回结果。

def func(s=""): # function

    shuzi = 0

    zimu = 0

    kongge = 0

    qita = 0

    for c in s: # 循环字符串.拿到每个字符

        if c.isdigit(): # 数字

            shuzi += 1

        elif c.isalpha():

            zimu+=1

        elif c == ' ':

            kongge += 1

        else:

            qita += 1

    return shuzi, zimu, kongge, qita

6.

def num(n1,n2):

    if n1>n2:

        return n1

    elif n1<n2:

        return n2

a=num(26,98)

print(a)

7.

def dic(dic):

    for k,v in dic.items():

        if len(v)>2:

            dic[k]=v[0:2]

    return dic

a=dic({1:'dsfgasdf',2:'sdfsdsd',3:'卡卡卡的双丰收'})

print(a)

8.

def list(input):

    dic={}

    if type(input)==type([]):

        for i in  range(0,len(input)):

            dic[i]=input[i]

        return dic

    elif type(input)!=type([]):

        return '请输入列表'

a=list([2,3,6,5,9,8])

print(a)

9.

def xx(姓名=input('姓名:'),性别=input('性别:'),年龄=input('年龄:'),学历=input('学历:')):

    student_msg={}

    student_msg['姓名']=姓名

    student_msg['性别'] = 性别

    student_msg['年龄'] = 年龄

    student_msg['学历'] = 学历

    return student_msg

a=xx()

print(a)

9.

def func(name, age,edu,sex ="男"):

    f = open("student.msg", mode="a", encoding="utf-8")

    f.write(name+"_"+str(age)+"_"+sex+"_"+edu+"\n")

    f.flush()

    f.close()

10.

def xx():

    while True:

        a=input('姓名：')

        if a.lower() == 'q':

            break

        else:

            student_msg={}

            student_msg['姓名']=a

            student_msg['性别'] = input('性别:')

            student_msg['年龄'] = input('年龄:')

            student_msg['学历'] = input('学历:')

    return student_msg

aa=xx()

print(aa)

11.

def ch(wjm,ynr,xnr):

    import os

    with open(wjm,'r',encoding='utf-8') as f1, open('a.txt','w',encoding='utf-8') as f2:

        for i in f1.readlines():

            a=i.replace(ynr,xnr)

            f2.write(a)

    os.remove(wjm)

    os.rename('a.txt',wjm)

ch('4.txt','alex','sb')

12.

def dl(username,password):

    count=0

    while count<=3:

        if username=='' and password=='':

            return ('登录成功')

            count=count+1

        else :

            return ('请重新输入：')

            count+=1

a=dl(12563,'')

print(a)