2019-11-11 day 6作业

def count1(list1,x):
    num=0
    for i in list1:
        if i==x:
            num+=1
    return num
list2=[1,1,2,2,2,3,2,1]
print(count1(list2,2))

def extend1(list1,x):
    for i in x:
        list1.append(i)
    return list1
list2=[1,2,3,3,4,4,5]
list3=[1,4,4,5,5,6,6]
print(extend1(list2,list3))


def index1(list1,ojb):
    for i in range(len(list1)):
        if list1[i]==ojb:
            return i

list2=[1,3,2,3,4,4,5]
print(index1(list2,1))

def reverse1(list1):
    for x in range(len(list1)//2):
        y=len(list1)-1-x
        list1[x],list1[y]=list1[y],list1[x]
    return list1
list2=[1,3,2,3,4,4,5]
print(reverse1(list2))