python-组合数据类

列表：由字符串创建一个作业评分列表，做增删改查询统计遍历操作。例如，查询第一个3分的下标，统计1分的同学有多少个，3分的同学有多少个等。

 s=list('kkkkk')
s.insert(3,2)
s.pop(3)
s[6]=1
print(s)
print('第一个1的位置是：',s.index('1'))
x=0
y=0
for i in range(len(s)):
    if s[i]=='3':
        x=x+1
        if x==1:
            y=i
print('三分个数为：',x,' ','第一个三分位置是：',y)
print('二分个数为：',s.count('2'))

字典：建立学生学号成绩字典，做增删改查遍历操作。

>>> dic=dict(zip([1,2,3],['98','100','88']))
>>> dic
{1: '98', 2: '100', 3: '88'}


>>> dic2={4:'95'}
>>> dic.update(dic2)
>>> dic
{1: '98', 2: '100', 3: '88', 4: '95'}


>>> dic.pop(2)
'100'
>>> dic
{1: '98', 3: '88', 4: '95'}



>>> dic
{1: '120', 3: '88', 4: '95'}
>>> del dic[3]
>>> dic
{1: '120', 4: '95'}


>>> dic[1]='120'
>>> dic
{1: '120', 3: '88', 4: '95'}


>>> dic
{1: '98', 3: '88', 4: '95'}
>>> dic.get(4)
'95'
>>> dic.get(5,'没有')
'没有'



>>> dic[4]
'95'


>>> dic.keys()
dict_keys([1, 3, 4])
>>> dic.values()
dict_values(['98', '88', '95'])


>>> dic.items()
dict_items([(1, '98'), (3, '88'), (4, '95')])

dict

列表，元组，字典，集合的遍历。

s=list(‘456132798‘)
t=set(‘4561327489‘)
c={‘小明‘:‘1‘,‘小红‘:‘3‘,‘小华‘:‘2‘}
x=(1, 2, 3, 4, 5 )
print(‘列表的遍历为:‘,end=‘‘)
for i in s:
    print(i,end=‘‘)
print()
print(‘元祖的遍历为:‘,end=‘‘)
for i in x:
    print(i,end=‘‘)
print()
print(‘字典key的遍历为:‘,end=‘‘)
for i in c:
    print(i,end=‘‘)
print()
print(‘字典value的遍历为:‘,end=‘‘)
for i in c.values():
    print(i,end=‘‘)
print()
print(‘数组的遍历为:‘,end=‘‘)
for i in x:
    print(i,end=‘‘)

 

 

'''
下载一首英文的歌词或文章，统计单词出现的次数，将所有,.？！替换为空格，将所有大写转换为小写。
'''
sr='''You're ?insecure
Don't know what for
You're turning heads through the door
Don't need make-up
to cover up
Being the way that you are is enough
Everyone else in the room can see it
Everyone else but you
Baby you light up my world like nobody else
The way that you flip your hair gets me overwhelmed
But when you smile at the ground it ain't hard to tell
You don't know Oh oh
You don't know you're beautiful
If only you saw what I can see
You'll understand why I want you so desperately
Right now I'm looking at you and I can't believe
You don't know Oh !oh
You don't know you're beautiful Oh oh
That's what makes you beautiful
So c-come on
You got it wrong
To prove I'm ,right '''

print(sr.count('you'))
for i in sr:
    sr=sr.replace(',','/t ')
    sr=sr.replace('!','/t ')
    sr=sr.replace('?','/t ')
print(sr)
for i in sr:
    sr=sr.upper()
print(sr)

 

 

英文词频统计实例

s='''Well I wonder could it be When I was dreaming about you baby
You were dreaming of me Call me crazy Call me blind To still be suffering
is stupid after all of this time Did I lose my love to someone better
And does she love you like I do I do, you know I really really do
Well hey So much I need to say Been lonely since the day The day you went away
So sad but true For me there‘s only you Been crying since the day
the day you went away.!?'''
print("do出现次数",s.count('do'))
s=s.replace(",","")
s=s.replace(‘.‘,‘‘)
s=s.replace(‘?‘,‘‘)
s=s.replace(‘!‘,‘‘)
s=s.replace(‘\n‘,‘‘)
s=s.lower()
s1=s.split(‘ ‘)
key=set(s1)
dic={}
for i in key:
    dic[i]=s.count(i)
wc=list(dic.items())
wc.sort(key=lambda x:x[1],reverse=True)
for i in range(10):
print(wc[i])