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Python 100 cases

2020-11-06 21:13:23 itread01

 For example 001: Combination of numbers 
 Title   There are four numbers :1、2、3、4, How many distinct three digit numbers can be formed without repeating numbers ? How many are each ?

 Program analysis   Traverse all possibilities , Shave off the repetitive ones .

total=0
for i in range(1,5):
    for j in range(1,5):
        for k in range(1,5):
            if ((i!=j)and(j!=k)and(k!=i)):
                print(i,j,k)
                total+=1
print(total)

 Easy way   use itertools Medium permutations that will do .

import itertools
sum2=0
a=[1,2,3,4]
for i in itertools.permutations(a,3):
    print(i)
    sum2+=1
print(sum2)
 For example 002:“ Personal tax calculation ”
 Title   The bonus paid by the enterprise is based on the profit . Profit (I) Less than or equal to 10 Ten thousand yuan , The prize money can be raised 10%; The profit is higher than 10 Ten thousand yuan , Lower than 20 Ten thousand yuan , Lower than 10 Ten thousand yuan part by 10% Royalty , Higher than 10 Ten thousand yuan , It's a percentage 7.5%;20 Ten thousand to 40 Between ten thousand , Higher than 20 Ten thousand yuan , It's a percentage 5%;40 Ten thousand to 60 Ten thousand is higher than 40 Ten thousand yuan , It's a percentage 3%;60 Ten thousand to 100 Between ten thousand , Higher than 60 Ten thousand yuan , It's a percentage 1.5%, Higher than 100 Ten thousand yuan , More than 100 Ten thousand yuan part by 1% Royalty , Enter the month's profit from the keyboard I, The total amount of bonus should be paid ?

 Program analysis   Divide the calculation between the slots .

profit=int(input('Show me the money: '))
bonus=0
thresholds=[100000,100000,200000,200000,400000]
rates=[0.1,0.075,0.05,0.03,0.015,0.01]
for i in range(len(thresholds)):
    if profit<=thresholds[i]:
        bonus+=profit*rates[i]
        profit=0
        break
    else:
        bonus+=thresholds[i]*rates[i]
        profit-=thresholds[i]
bonus+=profit*rates[-1]
print(bonus)
 For example 003: Perfect squared number 
 Title   An integer , It adds 100 And then it's a perfect square , Plus 168 It's another perfect square , What's the number, please ?

 Program analysis   Because 168 It's too small for an exponential explosion , So mathematical analysis can be omitted directly , Get the upper limit in the simplest way :

n=0
while (n+1)**2-n*n<=168:
    n+=1

print(n+1)

 The train of thought is : The worst is n The square sum of (n+1) The square of is just the difference 168, Because it's Square , There can't be a bigger gap than this .
 To judge whether it is a perfect square , The easiest way is : The value of the square root is decimal 0 that will do .
 Together :

n=0
while (n+1)**2-n*n<=168:
    n+=1

for i in range((n+1)**2):
    if i**0.5==int(i**0.5) and (i+168)**0.5==int((i+168)**0.5):
        print(i-100)

 For example 004: The day of the day 
 Title   Enter the date, month and year , Judge the day of the year ?

 Program analysis   Special circumstances , In leap years, consider adding one more day to February :

def isLeapYear(y):
    return (y%400==0 or (y%4==0 and y%100!=0))
DofM=[0,31,28,31,30,31,30,31,31,30,31,30]
res=0
year=int(input('Year:'))
month=int(input('Month:'))
day=int(input('day:'))
if isLeapYear(year):
    DofM[2]+=1
for i in range(month):
    res+=DofM[i]
print(res+day)

 For example 005: Three number sort 
 Title   Enter three integers x,y,z, Please output these three numbers from small to large .

 Program analysis   Practice hands to find a random sorting algorithm to achieve , If you're lazy, you just call the function directly .

raw=[]
for i in range(3):
    x=int(input('int%d: '%(i)))
    raw.append(x)
    
for i in range(len(raw)):
    for j in range(i,len(raw)):
        if raw[i]>raw[j]:
            raw[i],raw[j]=raw[j],raw[i]
print(raw)


raw2=[]
for i in range(3):
    x=int(input('int%d: '%(i)))
    raw2.append(x)
print(sorted(raw2))

 For example 006: Fibonacci series 
 Title   Fibonacci series .

 Program analysis   Fibonacci series (Fibonacci sequence), From 1,1 Start , Each of the latter is equal to the sum of the preceding two . The graph is convenient to implement recursively , Use loop for efficiency .

 Recursive realization 
def Fib(n):
    return 1 if n<=2 else Fib(n-1)+Fib(n-2)
print(Fib(int(input())))
    
 Simple realization 
target=int(input())
res=0
a,b=1,1
for i in range(target-1):
    a,b=b,a+b
print(a)

 For example 007:copy
 Title   Copy data from one list to another .

 Program analysis   Use list [:], I'm not sure I can call copy Module .

import copy
a = [1,2,3,4,['a','b']]

b = a                    #  Assignment 
c = a[:]                #  Light copy 
d = copy.copy(a)        #  Light copy 
e = copy.deepcopy(a)    #  Deep copy 

a.append(5)
a[4].append('c')

print('a=',a)
print('b=',b)
print('c=',c)
print('d=',d)
print('e=',e)

============ RESTART: F:\PyWorkspace\Python100\100examples\007.py ============
a= [1, 2, 3, 4, ['a', 'b', 'c'], 5]
b= [1, 2, 3, 4, ['a', 'b', 'c'], 5]
c= [1, 2, 3, 4, ['a', 'b', 'c']]
d= [1, 2, 3, 4, ['a', 'b', 'c']]
e= [1, 2, 3, 4, ['a', 'b']]

 For example 008: multiplication table 
 Title   Output  9*9  Multiplication table .

 Program analysis   Branch and column considerations , common 9 That's ok 9 Column ,i The control line ,j Control the column .

for i in range(1,10):
    for j in range(1,i+1):
        print('%d*%d=%2ld '%(i,j,i*j),end='')
    print()

 For example 009: Pause output for one second 
 Title   Pause output for one second .

 Program analysis   Use  time  Modular  sleep()  Function .

import time
for i in range(4):
    print(str(int(time.time()))[-2:])
    time.sleep(1)

 For example 010: Time for people to see 
 Title   Pause output for one second , And format the current time .

 Program analysis   Same as 009.

import time

for i in range(4):
    print(time.strftime('%Y-%m-%d %H:%M:%S',time.localtime(time.time())))
    time.sleep(1)
 For example 011: Raising rabbits 
 Title   There's a couple of Rabbits , Since the birth of 3 Rabbits are born once a month , After the third month, the rabbit gives birth to another pair of rabbits every month , If the rabbits don't die , Ask the total number of rabbits per month ?

 Program analysis   I think the solution of the original text is a little bit lame , No consideration of 3 Months of maturity , How can a child be born when he is still a baby ? Considering three months of maturity , You can build four profiles , among : January rabbits grow up to be February rabbits every month , February rabbit becomes March rabbit , March rabbit becomes adult rabbit , Adult rabbits ( Including the new mature March rabbit ) Give birth to an equal number of January rabbits .

month=int(input(' Breeding for months ?: '))
month_1=1
month_2=0
month_3=0
month_elder=0
for i in range(month):
    month_1,month_2,month_3,month_elder=month_elder+month_3,month_1,month_2,month_elder+month_3
    print(' The first %d Months in total '%(i+1),month_1+month_2+month_3+month_elder,' To the rabbit ')
    print(' among 1 Moon Rabbit :',month_1)
    print(' among 2 Moon Rabbit :',month_2)
    print(' among 3 Moon Rabbit :',month_3)
    print(' The adult rabbit :',month_elder)
 For example 012:100 To 200 The prime number of 
 Title   Judge 101-200 How many primes between , And output all prime numbers .

 Program analysis   How to judge prime numbers : Remove by a number 2 To sqrt( This number ), If it can be divided , The number is not a prime number , On the contrary, it's a prime .  use else Code can be further simplified .

import math
for i in range(100,200):
    flag=0
    for j in range(2,round(math.sqrt(i))+1):
        if i%j==0:
            flag=1
            break
    if flag:
        continue
    print(i)


print('\nSimplify the code with "else"\n')


for i in range(100,200):
    for j in range(2,round(math.sqrt(i))+1):
        if i%j==0:
            break
    else:
        print(i)

 For example 013: All daffodils count 
 Title   Print out all " Number of Narcissus ", So called " Number of Narcissus " It means a three digit number , The number cubes are equal to the number itself . for example :153 It's a " Number of Narcissus ", Because 153=1 The third power of +5 The third power of +3 The third power of .

 Program analysis   utilize for Loop control 100-999 Number , Each number is decomposed into bits , ten , Hundred bit .

for i in range(100,1000):
    s=str(i)
    one=int(s[-1])
    ten=int(s[-2])
    hun=int(s[-3])
    if i == one**3+ten**3+hun**3:
        print(i)
 For example 014: Decompose the prime factor 
 Title   Factoring an integer into prime factors . for example : Input 90, Print out 90=233*5.

 Program analysis   There's no need to judge whether it's a prime number at all , From 2 Start traversing the number itself , It must be the smallest prime number that can be divisible .

target=int(input(' Enter an integer :'))
print(target,'= ',end='')

if target<0:
    target=abs(target)
    print('-1*',end='')

flag=0
if target<=1:
    print(target)
    flag=1


while True:
    if flag:
        break
    for i in range(2,int(target+1)):
        if target%i==0:
            print("%d"%i,end='')
            if target==i:
                flag=1
                break
            print('*',end='')
            target/=i
            break
        
 For example 015: Score filing 
 Title   Use the nest of conditional operators to complete this problem : Academic performance >=90 The students who are divided into two parts A Express ,60-89 Between the points B Express ,60 Divide the following uses C Express .

 Program analysis   Judge by condition .

points=int(input(' Enter the score :'))
if points>=90:
    grade='A'
elif points<60:
    grade='C'
else:
    grade='B'
print(grade)
 For example 016: Output date 
 Title   Output date in specified format .

 Program analysis   Use  datetime  Module .

import datetime
print(datetime.date.today())
print(datetime.date(2333,2,3))
print(datetime.date.today().strftime('%d/%m/%Y'))
day=datetime.date(1111,2,3)
day=day.replace(year=day.year+22)
print(day)
 For example 017: Strings make up 
 Title   Type a line of characters , The Chinese and English letters are counted respectively 、 Space 、 The number of numbers and other characters .

 Program analysis   utilize  while  or  for  Sentence , If the input character is not  ‘\n’.

string=input(" Type the string :")
alp=0
num=0
spa=0
oth=0
for i in range(len(string)):
    if string[i].isspace():
        spa+=1
    elif string[i].isdigit():
        num+=1
    elif string[i].isalpha():
        alp+=1
    else:
        oth+=1
print('space: ',spa)
print('digit: ',num)
print('alpha: ',alp)
print('other: ',oth)

 For example 018: Repeater addition 
 Title   seek s=a+aa+aaa+aaaa+aa…a Value , among a It's a number . for example 2+22+222+2222+22222( At this time, there is 5 Add up the numbers ), The addition of several numbers is controlled by the keyboard .

 Program analysis   Solve with a string .

a=input(' Added number :')
n=int(input(' Add it a few times ?:'))
res=0
for i in range(n):
    res+=int(a)
    a+=a[0]
print(' The result is :',res)

 For example 019: It's over 
 Title   If a number is exactly equal to the sum of its factors , This number is called " It's over ". for example 6=1+2+3. Programming finds 1000 All the completions within .

 Program analysis   Add each pair of factors to the set , This process has gone automatically . The final result requires not to calculate itself .

def factor(num):
    target=int(num)
    res=set()
    for i in range(1,num):
        if num%i==0:
            res.add(i)
            res.add(num/i)
    return res

for i in range(2,1001):
    if i==sum(factor(i))-i:
        print(i)

 For example 020: High altitude parabolic 
 Title   A ball from 100 Free fall at meter height , Jump back to half of the original altitude after each landing ; And then fall , Ask it in the 10 On the second landing , How many meters has it passed ? The first 10 How high is the rebound ?

 Program analysis   Nothing 

high=200.
total=100
for i in range(10):
    high/=2
    total+=high
    print(high/2)
print(' The total length is :',total)
 For example 021: Monkeys steal peaches 
 Title   Monkeys eat peaches : The monkey picked several peaches on the first day , I ate half of it immediately , It's not addictive , I ate one more and ate half of the remaining peaches the next morning , One more . After that, I ate half and one of the rest of the day before every morning . To the first 10 When I want to eat again in the morning , There's only one peach left . Ask how much you picked on the first day .

 Program analysis   Infer backward according to the rules : The monkey has a peach , He stole a peach , I think it's not enough. I stole the same amount of peaches as my hands , They stole 9 God .

peach=1
for i in range(9):
    peach=(peach+1)*2
print(peach)
 For example 022: Competitors 
 Title   Two table tennis teams play , Three people each . Team a is a,b,c Three people , Team B is for x,y,z Three people . The list of matches has been drawn . Someone asked the players for the list of the game .a Said he didn't agree with x Than ,c Said he didn't agree with x,z Than , Please find out the list of players in the three teams by programming .

 Program analysis   Find three opponents that don't repeat under the conditions .

a=set(['x','y','z'])
b=set(['x','y','z'])
c=set(['x','y','z'])
c-=set(('x','y'))
a-=set('x')
for i in a:
    for j in b:
        for k in c:
            if len(set((i,j,k)))==3:
                print('a:%s,b:%s,c:%s'%(i,j,k))
 For example 023: Draw a diamond 
 Title   Print out the following pattern ( The diamond ):

    *
   ***
  *****
 *******
  *****
   ***
    *

 Program analysis   Send back the call .

def draw(num):
    a="*"*(2*(4-num)+1)
    print(a.center(9,' '))
    if num!=1:
        draw(num-1)
        print(a.center(9,' '))
draw(4)

 For example 024: Fibonacci series II
 Title   There's a sequence of scores :2/1,3/2,5/3,8/5,13/8,21/13… This is the first sequence 20 Sum of items .

 Program analysis   It's the last term in the Fibonacci sequence, except for the previous one .

a = 2.0
b = 1.0
s = 0
for n in range(1,21):
    s += a / b
    a,b = a + b,a
print (s)
 For example 025:  Factorial summation 
 Title   seek 1+2!+3!+…+20! And .

 Program analysis  1+2!+3!+…+20!=1+2(1+3(1+4(…20(1))))

res=1
for i in range(20,1,-1):
    res=i*res+1
print(res)
 For example 026: Go back to factorial 
 Title   Using recursive method to find 5!.

 Program analysis   Send back the call .

def factorial(n):
    return n*factorial(n-1) if n>1 else 1
print(factorial(5))

 For example 027: Recursive output 
 Title   Using recursive function to call , Will enter the 5 Characters , Print it out in reverse order .

 Program analysis   It's a stupid way to go back .

def rec(string):
    if len(string)!=1:
        rec(string[1:])
    print(string[0],end='')

rec(input('string here:'))

 For example 028: To find the arithmetic sequence step by step 
 Title   Yes 5 Individuals sitting together , Ask the fifth man how old he is ? He said Biddy 4 Personal big 2 Year old . Ask No 4 Personal age , He said Biddy 3 Personal big 2 Year old . Ask a third person , Again, Biddy 2 People are two years old . Ask No 2 Individual , Two years older than the first one . Finally, ask the first person , He said it was 10 Year old . How old is the fifth person ?

 Program analysis   Just an arithmetic sequence .

def age(n):
    if n==1:
        return 10
    return 2+age(n-1)
print(age(5))

 For example 029: Reverse output 
 Title   Give one not more than 5 The positive integer of the bit , requirement : One 、 How many digits is it , Two 、 Print the numbers in reverse order .

 Program analysis   Learn to break down every digit , It's always easier to use strings .

n=int(input(' Enter a positive integer :'))
n=str(n)
print('%d Number of digits '%len(n))
print(n[::-1])

 For example 030: Palindrome number 
 Title   One 5 Number of digits , Judge whether it is palindrome number . namely 12321 It's palindrome number , One is the same as ten thousand , Ten is the same as a thousand .

 Program analysis   It's more convenient to use a string , Even if the input is not a number ok.

n=input(" Whatever you type in :")
a=0
b=len(n)-1
flag=True
while a<b:
    if n[a]!=n[b]:
        print(' It's not a palindrome string ')
        flag=False
        break
    a,b=a+1,b-1
if flag:
    print(' It's a palindrome ')

 For example 031: Letters recognize words 
 Title   Please enter the first letter of the day of the week to judge the day of the week , If the first letter is the same , Then continue to judge the second letter .

 Program analysis   Here we use the form of a dictionary to store the comparison relationship directly .

weekT={'h':'thursday',
       'u':'tuesday'}
weekS={'a':'saturday',
       'u':'sunday'}
week={'t':weekT,
      's':weekS,
      'm':'monday',
      'w':'wensday',
      'f':'friday'}
a=week[str(input(' Please enter the first letter :')).lower()]
if a==weekT or a==weekS:
    print(a[str(input(' Please enter the second letter :')).lower()])
else:
    print(a)

 For example 032: Reverse output II
 Title   Output the values of the list in reverse order .

 Program analysis   Nothing .

a = ['one', 'two', 'three']
print(a[::-1])
 For example 033: List to string 
 Title   Separate the list by comma .

 Program analysis   Nothing .

L = [1,2,3,4,5]
print(','.join(str(n) for n in L))

 For example 034: Call function 
 Title   Practice function calls .

 Program analysis   Nothing .

def hello():
    print('Hello World!')
def helloAgain():
    for i in range(2):
        hello()

if __name__=='__main__':
    helloAgain()

 For example 035: Set the output color 
 Title   Text color setting .

 Program analysis   Nothing .

class bcolors:
    HEADER = '\033[95m'
    OKBLUE = '\033[94m'
    OKGREEN = '\033[92m'
    WARNING = '\033[93m'
    FAIL = '\033[91m'
    ENDC = '\033[0m'
    BOLD = '\033[1m'
    UNDERLINE = '\033[4m'
print(bcolors.WARNING + " The color and font of the warning ?" + bcolors.ENDC)
 For example 036: Count prime numbers 
 Title   seek 100 Prime numbers within .

 Program analysis   use else Execute for The reward code of the circle ( If for It's a normal ending , Not break).

lo=int(input(' Lower limit :'))
hi=int(input(' ceiling :'))
for i in range(lo,hi+1):
    if i > 1:
        for j in range(2,i):
            if (i % j) == 0:
                break
        else:
            print(i)
 For example 037: Sort 
 Title   Yes 10 Sort by number .

 Program analysis   In the same case 005.

raw=[]
for i in range(10):
    x=int(input('int%d: '%(i)))
    raw.append(x)
    
for i in range(len(raw)):
    for j in range(i,len(raw)):
        if raw[i]>raw[j]:
            raw[i],raw[j]=raw[j],raw[i]
print(raw)

 For example 038: The sum of the diagonals of a matrix 
 Title   Ask for one 3*3 The sum of the main diagonal elements of a matrix .

 Program analysis   Nothing .

mat=[[1,2,3],
     [3,4,5],
     [4,5,6]
    ]
res=0
for i in range(len(mat)):
    res+=mat[i][i]
print(res)

 For example 039: Ordered list insert elements 
 Title   There's an ordered array . Now enter a number , It is required to insert it into the array according to the original rule .

 Program analysis   First judge whether the number is greater than the last number , Then consider the case of inserting the middle number , The number after this element is inserted , Move back one position in turn .

lis=[1,10,100,1000,10000,100000]
n=int(input('insert a number: '))
lis.append(n)
for i in range(len(lis)-1):
    if lis[i]>=n:
        for j in range(i,len(lis)):
            lis[j],lis[-1]=lis[-1],lis[j]
        break
print(lis)
 For example 040: Reverse list 
 Title   Output an array in reverse order .

 Program analysis   Switch positions in turn , Or call directly reverse Method .

lis=[1,10,100,1000,10000,100000]
for i in range(int(len(lis)/2)):
    lis[i],lis[len(lis)-1-i]=lis[len(lis)-1-i],lis[i]
print(' The first kind of implementation :')
print(lis)


lis=[1,10,100,1000,10000,100000]
print(' The second implementation :')
lis.reverse()
print(lis)

 For example 041: Class methods and variables 
 Title   Imitate the use of static variables .

 Program analysis   Construction class , Understand the methods and variables of a class .

def dummy():
    i=0
    print(i)
    i+=1

class cls:
    i=0
    def dummy(self):
        print(self.i)
        self.i+=1

a=cls()
for i in range(50):
    dummy()
    a.dummy()
 For example 042: Variable scope 
 Title   Learn to use auto Define the usage of variables .

 Program analysis  python Variable scope in .

i=0
n=0
def dummy():
    i=0
    print(i)
    i+=1
def dummy2():
    global n
    print(n)
    n+=1
print(' A variable with the same name inside a function ')
for j in range(20):
    print(i)
    dummy()
    i+=1
print('global Declare the variable with the same name ')
for k in range(20):
    print(n)
    dummy2()
    n+=10

 For example 043: Scope 、 Class methods and variables 
 Title   Imitate static variables (static) Another case .

 Program analysis   Comprehensive example 041 And examples 042.

class dummy:
    num=1
    def Num(self):
        print('class dummy num:',self.num)
        print('global num: ',num)
        self.num+=1

n=dummy()
num=1
for i in range(5):
    num*=10
    n.Num()
 For example 044: Matrix addition 
 Title   Calculate the addition of two matrices .

 Program analysis   Build a new matrix , Use  for  Iterate and extract  X  and  Y  The value of the corresponding position in the matrix , Add it and put it in the corresponding position of the new matrix .

X = [[12,7,3],
    [4 ,5,6],
    [7 ,8,9]]
 
Y = [[5,8,1],
    [6,7,3],
    [4,5,9]]
 
res=[[0,0,0],
    [0,0,0],
    [0,0,0]]
for i in range(len(res)):
    for j in range(len(res[0])):
        res[i][j]=X[i][j]+Y[i][j]
print(res)

 For example 045: Sum up 
 Title   Statistics  1  To  100  The sum of the .

 Program analysis   Nothing 

res=0
for i in range(1,101):
    res+=i
print(res)
 For example 046: Break the circle 
 Title   Square the input number , If the square is less than  50  Then exit .

 Program analysis   Nothing 

while True:
    try:
        n=float(input(' Enter a number :'))
    except:
        print(' Input error ')
        continue
    dn=n**2
    print(' Its square is :',dn)
    if dn<50:
        print(' The square is less than 50, sign out ')
        break

 For example 047: Functions exchange variables 
 Title   Two variables are interchanged by functions .

 Program analysis   Nothing 

def exc(a,b):
    return (b,a)
a=0
b=10
a,b=exc(a,b)
print(a,b)
 For example 048: The number is bigger than the size 
 Title   Number comparison .

 Program analysis   Nothing 

a=int(input('a='))
b=int(input('b='))
if a<b:
    print('a<b')
elif a>b:
    print('a>b')
else:
    print('a=b')

 For example 049:lambda
 Title   Use lambda To create anonymous functions .

 Program analysis   Nothing 

Max=lambda x,y:x*(x>=y)+y*(y>x)
Min=lambda x,y:x*(x<=y)+y*(y<x)

a=int(input('1:'))
b=int(input('2:'))

print(Max(a,b))
print(Min(a,b))

 For example 050: Random numbers 
 Title   Output a random number .

 Program analysis   Use  random  Module .

import random
print(random.uniform(10,20))
 For example 051: Bitwise and 
 Title   Learn to use bitwise and  & .

 Program analysis  0&0=0; 0&1=0; 1&0=0; 1&1=1.

a=0o77
print(a)
b=a&3
print(b)
b=b&7
print(b)
 For example 052: Press bit or 
 Title   Learn to use bitwise OR  | .

 Program analysis  0|0=0; 0|1=1; 1|0=1; 1|1=1

a=0o77
print(a|3)
print(a|3|7)

 For example 053: According to position XOR 
 Title   Learn to use bitwise XOR  ^ .

 Program analysis  0^0=0; 0^1=1; 1^0=1; 1^1=0

a=0o77
print(a^3)
print(a^3^7)

 For example 054: Bit inversion 、 Bit shift 
 Title   Take an integer a It starts at the right end 4~7 position .

 Program analysis   Think about it this way :
(1) First of all a Move right 4 position .
(2) Set a low 4 All the seats are 1, The rest are all 0 The number of . You can use (0<<4)
(3) The above two are carried out & Operations .

a=int(input(' Enter a number : '))
b=0                 #     0
b=~b                #     1
b=b<<4              # 10000
b=~b                #  1111
c=a>>4
d=c&b
print('a:',bin(a))
print('b:',bin(b))
print('c:',bin(c))
print('d:',bin(d))

 For example 055: According to the not 
 Title   Learn to use positional inversion ~.

 Program analysis  ~0=1; ~1=0;

print(~234)
print(~~234)

 For example 056: Circle 
 Title   Drawing , Learn to use circle Draw a circle .

 Program analysis   Nothing .

from tkinter import *
canvas=Canvas(width=800,height=600,bg='yellow')
canvas.pack(expand=YES,fill=BOTH)
k=1
j=1
for i in range(26):
    canvas.create_oval(310-k,250-k,310+k,250+k,width=1)
    k+=j
    j+=0.3
mainloop()
 For example 057: Draw a line 
 Title   Drawing , Learn to use line Draw a straight line .

 Program analysis   Nothing .

if __name__ == '__main__':
    from tkinter import *
 
    canvas = Canvas(width=300, height=300, bg='green')   
    canvas.pack(expand=YES, fill=BOTH)                  
    x0 = 263
    y0 = 263
    y1 = 275
    x1 = 275
    for i in range(19):
        canvas.create_line(x0,y0,x0,y1, width=1, fill='red')
        x0 = x0 - 5
        y0 = y0 - 5
        x1 = x1 + 5
        y1 = y1 + 5
 
    x0 = 263
    y1 = 275
    y0 = 263
    for i in range(21):
        canvas.create_line(x0,y0,x0,y1,fill = 'red')
        x0 += 5
        y0 += 5
        y1 += 5
 
    mainloop()
 For example 058: Draw a rectangle 
 Title   Drawing , Learn to use rectangle Draw a square .

 Program analysis   Nothing .

if __name__ == '__main__':
    from tkinter import *
    root = Tk()
    root.title('Canvas')
    canvas = Canvas(root,width = 400,height = 400,bg = 'yellow')
    x0 = 263
    y0 = 263
    y1 = 275
    x1 = 275
    for i in range(19):
        canvas.create_rectangle(x0,y0,x1,y1)
        x0 -= 5
        y0 -= 5
        x1 += 5
        y1 += 5
        
    canvas.pack()
    root.mainloop()
 For example 059: Drawing ( Ugly )
 Title   Drawing , Comprehensive examples .

 Program analysis   Ugly .

if __name__  == '__main__':
    from tkinter import *
    canvas = Canvas(width = 300,height = 300,bg = 'green')
    canvas.pack(expand = YES,fill = BOTH)
    x0 = 150
    y0 = 100
    canvas.create_oval(x0 - 10,y0 - 10,x0 + 10,y0 + 10)
    canvas.create_oval(x0 - 20,y0 - 20,x0 + 20,y0 + 20)
    canvas.create_oval(x0 - 50,y0 - 50,x0 + 50,y0 + 50)
    import math
    B = 0.809
    for i in range(16):
        a = 2 * math.pi / 16 * i
        x = math.ceil(x0 + 48 * math.cos(a))
        y = math.ceil(y0 + 48 * math.sin(a) * B)
        canvas.create_line(x0,y0,x,y,fill = 'red')
    canvas.create_oval(x0 - 60,y0 - 60,x0 + 60,y0 + 60)
    

    for k in range(501):
        for i in range(17):
            a = (2 * math.pi / 16) * i + (2 * math.pi / 180) * k
            x = math.ceil(x0 + 48 * math.cos(a))
            y = math.ceil(y0 + 48 + math.sin(a) * B)
            canvas.create_line(x0,y0,x,y,fill = 'red')
        for j in range(51):
            a = (2 * math.pi / 16) * i + (2* math.pi / 180) * k - 1
            x = math.ceil(x0 + 48 * math.cos(a))
            y = math.ceil(y0 + 48 * math.sin(a) * B)
            canvas.create_line(x0,y0,x,y,fill = 'red')
    mainloop()

 For example 060: String length 
 Title   Calculate string length .

 Program analysis   Nothing .

s='zhangguang101'
print(len(s))

 For example 061: Yang Hui triangle 
 Title   Print out the first ten lines of Yang Hui's triangle .

 Program analysis   Nothing .

def generate(numRows):
    r = [[1]]
    for i in range(1,numRows):
        r.append(list(map(lambda x,y:x+y, [0]+r[-1],r[-1]+[0])))
    return r[:numRows]
a=generate(10)
for i in a:
    print(i)
 For example 062: Query string 
 Title   Query string .

 Program analysis   Nothing .

s1='aabbxuebixuebi'
s2='ab'
s3='xue'
print(s1.find(s2))
print(s1.find(s3))
 For example 063: Draw an ellipse 
 Title   Draw an ellipse .

 Program analysis   Use  tkinter.

if __name__ == '__main__':
    from tkinter import *
    x = 360
    y = 160
    top = y - 30
    bottom = y - 30
    
    canvas = Canvas(width = 400,height = 600,bg = 'white')
    for i in range(20):
        canvas.create_oval(250 - top,250 - bottom,250 + top,250 + bottom)
        top -= 5
        bottom += 5
    canvas.pack()
    mainloop()
 For example 064: Draw an ellipse 、 rectangular 
 Title   utilize ellipse  and  rectangle  Drawing ..

 Program analysis   Nothing .

if __name__ == '__main__':
    from tkinter import *
    canvas = Canvas(width = 400,height = 600,bg = 'white')
    left = 20
    right = 50
    top = 50
    num = 15
    for i in range(num):
        canvas.create_oval(250 - right,250 - left,250 + right,250 + left)
        canvas.create_oval(250 - 20,250 - top,250 + 20,250 + top)
        canvas.create_rectangle(20 - 2 * i,20 - 2 * i,10 * (i + 2),10 * ( i + 2))
        right += 5
        left += 5
        top += 10

    canvas.pack()
    mainloop()
 For example 065: Draw a combination of figures 
 Title   One of the most beautiful patterns .

 Program analysis   Nothing .

import math
from tkinter import *

class PTS:
    def __init__(self):
        self.x = 0
        self.y = 0
points = []

def LineToDemo():
    screenx = 400
    screeny = 400
    canvas = Canvas(width = screenx,height = screeny,bg = 'white')

    AspectRatio = 0.85
    MAXPTS = 15
    h = screeny
    w = screenx
    xcenter = w / 2
    ycenter = h / 2
    radius = (h - 30) / (AspectRatio * 2) - 20
    step = 360 / MAXPTS
    angle = 0.0
    for i in range(MAXPTS):
        rads = angle * math.pi / 180.0
        p = PTS()
        p.x = xcenter + int(math.cos(rads) * radius)
        p.y = ycenter - int(math.sin(rads) * radius * AspectRatio)
        angle += step
        points.append(p)
    canvas.create_oval(xcenter - radius,ycenter - radius,
                       xcenter + radius,ycenter + radius)
    for i in range(MAXPTS):
        for j in range(i,MAXPTS):
            canvas.create_line(points[i].x,points[i].y,points[j].x,points[j].y)

    canvas.pack()
    mainloop()
if __name__ == '__main__':
    LineToDemo()
 For example 066: Three number sort 
 Title   Input 3 Number a,b,c, Output in order of size .

 Program analysis   In the same case 005.

raw=[]
for i in range(3):
    x=int(input('int%d: '%(i)))
    raw.append(x)
    
for i in range(len(raw)):
    for j in range(i,len(raw)):
        if raw[i]>raw[j]:
            raw[i],raw[j]=raw[j],raw[i]
print(raw)


raw2=[]
for i in range(3):
    x=int(input('int%d: '%(i)))
    raw2.append(x)
print(sorted(raw2))

 For example 067: Swap places 
 Title   Input array , The biggest exchange with the first element , The smallest exchange with the last element , Output array .

 Program analysis   Nothing .

li=[3,2,5,7,8,1,5]

li[-1],li[li.index(min(li))]=li[li.index(min(li))],li[-1]

m=li[0]
ind=li.index(max(li))
li[0]=li[ind]
li[ind]=m

print(li)

 For example 068: Rotation sequence 
 Title   Yes n An integer , Move the preceding numbers backward in order m A place , Finally m The number becomes the first m Number 

 Program analysis   Nothing .

from collections import *
li=[1,2,3,4,5,6,7,8,9]
deq=deque(li,maxlen=len(li))
print(li)
deq.rotate(int(input('rotate:')))
print(list(deq))
 For example 069: Report number 
 Title   Yes n A circle of individuals , Sequence number . Count from the first person ( From 1 To 3 Report number ), Where to report 3 Of the people out of the circle , What's the last one left behind .

 Program analysis   Nothing .

if __name__ == '__main__':
    nmax = 50
    n = int(input(' Please enter the total number of people :'))
    num = []
    for i in range(n):
        num.append(i + 1)
 
    i = 0
    k = 0
    m = 0
 
    while m < n - 1:
        if num[i] != 0 : k += 1
        if k == 3:
            num[i] = 0
            k = 0
            m += 1
        i += 1
        if i == n : i = 0
 
    i = 0
    while num[i] == 0: i += 1
    print(num[i])
 For example 070: String length II
 Title   Write a function , Find the length of a string , stay main Type the string in the function , And output its length .

 Program analysis   Nothing .

def lenofstr(s):
    return len(s)

print(lenofstr('tanxiaofengsheng'))

 For example 071: Input and output 
 Title   Write input() and output() Function input , Output 5 Student records .

 Program analysis   Nothing .

N = 3
#stu
#num : string
#name : string
#score[4]: list
student = []
for i in range(5):
    student.append(['','',[]])
 
def input_stu(stu):
    for i in range(N):
        stu[i][0] = input('input student num:\n')
        stu[i][1] = input('input student name:\n')
        for j in range(3):
            stu[i][2].append(int(input('score:\n')))
 
def output_stu(stu):
    for i in range(N):
        print ('%-6s%-10s' % ( stu[i][0],stu[i][1] ))
        for j in range(3):
            print ('%-8d' % stu[i][2][j])
 
if __name__ == '__main__':
    input_stu(student)
    print (student)
    output_stu(student)

 For example 072: Create a connection string 
 Title   Create a link string .

 Program analysis   The original is not very reliable .

class Node:

    def __init__(self, data):
        self.data = data
        self.next = None

    def get_data(self):
        return self.data

class List:

    def __init__(self, head):
        self.head = head

    def is_empty(self): 
        return self.get_len() == 0

    def get_len(self):  
        length = 0
        temp = self.head
        while temp is not None:
            length += 1
            temp = temp.next
        return length

    def append(self, node):
        temp = self.head
        while temp.next is not None:
            temp = temp.next
        temp.next = node

    def delete(self, index): 
        if index < 1 or index > self.get_len():
            print(" The positioning is unreasonable ")
            return
        if index == 1:
            self.head = self.head.next
            return
        temp = self.head
        cur_pos = 0
        while temp is not None:
            cur_pos += 1
            if cur_pos == index-1:
                temp.next = temp.next.next
            temp = temp.next

    def insert(self, pos, node):
        if pos < 1 or pos > self.get_len():
            print(" The insertion node position is unreasonable ")
            return
        temp = self.head
        cur_pos = 0
        while temp is not Node:
            cur_pos += 1
            if cur_pos == pos-1:
                node.next = temp.next
                temp.next =node
                break
            temp = temp.next

    def reverse(self, head):
        if head is None and head.next is None:
            return head
        pre = head
        cur = head.next
        while cur is not None:
            temp = cur.next
            cur.next = pre
            pre = cur
            cur = temp
        head.next = None
        return pre

    def print_list(self, head):
        init_data = []
        while head is not None:
            init_data.append(head.get_data())
            head = head.next
        return init_data

if __name__=='__main__':
    head=Node('head')
    link=List(head)
    for i in range(10):
        node=Node(i)
        link.append(node)
    print(link.print_list(head))

 For example 073: Reverse output concatenation 
 Title   Output a concatenated column in reverse .

 Program analysis   Nothing .

class Node:

    def __init__(self, data):
        self.data = data
        self.next = None

    def get_data(self):
        return self.data

class List:

    def __init__(self, head):
        self.head = head

    def is_empty(self): 
        return self.get_len() == 0

    def get_len(self):  
        length = 0
        temp = self.head
        while temp is not None:
            length += 1
            temp = temp.next
        return length

    def append(self, node):
        temp = self.head
        while temp.next is not None:
            temp = temp.next
        temp.next = node

    def delete(self, index): 
        if index < 1 or index > self.get_len():
            print(" The positioning is unreasonable ")
            return
        if index == 1:
            self.head = self.head.next
            return
        temp = self.head
        cur_pos = 0
        while temp is not None:
            cur_pos += 1
            if cur_pos == index-1:
                temp.next = temp.next.next
            temp = temp.next

    def insert(self, pos, node):
        if pos < 1 or pos > self.get_len():
            print(" The insertion node position is unreasonable ")
            return
        temp = self.head
        cur_pos = 0
        while temp is not Node:
            cur_pos += 1
            if cur_pos == pos-1:
                node.next = temp.next
                temp.next =node
                break
            temp = temp.next

    def reverse(self, head):
        if head is None and head.next is None:
            return head
        pre = head
        cur = head.next
        while cur is not None:
            temp = cur.next
            cur.next = pre
            pre = cur
            cur = temp
        head.next = None
        return pre

    def print_list(self, head):
        init_data = []
        while head is not None:
            init_data.append(head.get_data())
            head = head.next
        return init_data

if __name__=='__main__':
    head=Node('head')
    link=List(head)
    for i in range(10):
        node=Node(i)
        link.append(node)
    print(link.print_list(head))
    print(link.print_list(link.reverse(head)))
 For example 074: Sort the list 、 Connect 
 Title   List sorting and linking .

 Program analysis   Sorting can be done using  sort()  Method , The connection can use  +  No. or  extend()  Method .

a=[2,6,8]
b=[7,0,4]
a.extend(b)
a.sort()
print(a)
 For example 075: confused 
 Title   Just relax , A simple question .

 Program analysis   Who knows what .

if __name__ == '__main__':
    for i in range(5):
        n = 0
        if i != 1: n += 1
        if i == 3: n += 1
        if i == 4: n += 1
        if i != 4: n += 1
        if n == 3: print (64 + i)
 For example 076: Do function 
 Title   Write a function , Input n Even number , Call function to find 1/2+1/4+…+1/n, When input n When it is odd , Call function 1/1+1/3+…+1/n

 Program analysis   Nothing .

def peven(n):
    i = 0
    s = 0.0
    for i in range(2,n + 1,2):
        s += 1.0 / i
    return s
 
def podd(n):
    s = 0.0
    for i in range(1, n + 1,2):
        s += 1.0 / i
    return s
 
def dcall(fp,n):
    s = fp(n)
    return s
 
if __name__ == '__main__':
    n = int(input('input a number: '))
    if n % 2 == 0:
        sum = dcall(peven,n)
    else:
        sum = dcall(podd,n)
    print (sum)
 For example 077: Traverse the list 
 Title   Loop output list 

 Program analysis   Nothing .

l=['moyu','niupi','xuecaibichi','shengfaji','42']
for i in range(len(l)):
    print(l[i])
 For example 078: Dictionaries 
 Title   Find the oldest person , And output . Please find out what's wrong with the program .

 Program analysis   Nothing .

if __name__ == '__main__':
    person = {"li":18,"wang":50,"zhang":20,"sun":22}
    m = 'li'
    for key in person.keys():
        if person[m] < person[key]:
            m = key
 
    print ('%s,%d' % (m,person[m]))
 For example 079: String sort 
 Title   String sort .

 Program analysis   Nothing .

l=['baaa','aaab','aaba','aaaa','abaa']
l.sort()
print(l)
 For example 080: The monkey divides the peach 
 Title   There is a pile of peaches on the beach , Five monkeys to divide . The first monkey divided the pile of peaches into five parts , One more , The monkey threw one more into the sea , Took a share of . The second monkey divided the remaining peaches into five parts , One more , It also throws one more into the sea , Took a share of , Third 、 Fourth 、 The fifth monkey did this , Ask how many peaches there are at least on the beach ?

 Program analysis   Nothing .

if __name__ == '__main__':
    i = 0
    j = 1
    x = 0
    while (i < 5) :
        x = 4 * j
        for i in range(0,5) :
            if(x%4 != 0) :
                break
            else :
                i += 1
            x = (x/4) * 5 +1
        j += 1
    print(x)

    for p in range(5):
        x=(x-1)/5*4
    print(x)
 For example 081: Ask for the unknowns 
 Title  809*??=800*??+9*??  among ?? Two digits for , 809*?? It's four digits ,8*?? The results are in two digits ,9*?? The result is 3 Number of digits . seek ?? Two digits for , And 809*?? The result after .

 Program analysis   Nothing .

a = 809
for i in range(10,100):
    b = i * a
    if b >= 1000 and b <= 10000 and 8 * i < 100 and 9 * i >= 100:
        print(b,' = 800 * ', i, ' + 9 * ', i)


for i in range(10,100):
    if 8*i>99 or 9*i<100:
        continue
    if 809*i==800*i+9*i:
        print(i)
        break

 For example 082: Carry to decimal 
 Title   Conversion from octave to decimal 

 Program analysis   Nothing .

n=eval('0o'+str(int(input(' Octal input :'))))
print(n)

 For example 083: Make odd numbers 
 Title   seek 0—7 The odd number that can be made up of .

 Program analysis 

 Make up 1 The number of digits is 4 One .1,3,5,7 End 

 Make up 2 The number of digits is 7*4 One . The first one can't be for 0

 Make up 3 The number of digits is 784 One . In the middle 

 Make up 4 The number of digits is 788*4 One .

if __name__ == '__main__':
    sum = 4
    s = 4
    for j in range(2,9):
        print (sum)
        if j <= 2:
            s *= 7
        else:
            s *= 8
        sum += s
    print('sum = %d' % sum)
 For example 084: Connection string 
 Title   Connection string .

 Program analysis   Nothing .

delimiter = ','
mylist = ['Brazil', 'Russia', 'India', 'China']
print(delimiter.join(mylist))
 For example 085: to be divisible by 
 Title   Enter an odd number , Then judge at least a few  9  The result of division is an integer .

 Program analysis  999999 / 13 = 76923.

if __name__ == '__main__':
    zi = int(input(' Enter a number :'))
    n1 = 1
    c9 = 1
    m9 = 9
    sum = 9
    while n1 != 0:
        if sum % zi == 0:
            n1 = 0
        else:
            m9 *= 10
            sum += m9
            c9 += 1
    print ('%d  One  9  Can be  %d  to be divisible by  : %d' % (c9,zi,sum))
    r = sum / zi
    print ('%d / %d = %d' % (sum,zi,r))
 For example 086: Connection string II
 Title   Two string connectors .

 Program analysis   Nothing .

a='guangtou'
b='feipang'
print(b+a)
 For example 087: Access class members 
 Title   The answer is ( Structure variable passing ).

 Program analysis   Nothing .

if __name__ == '__main__':
    class student:
        x = 0
        c = 0
    def f(stu):
        stu.x = 20
        stu.c = 'c'
    a= student()
    a.x = 3
    a.c = 'a'
    f(a)
    print(a.x,a.c)
 For example 088: Print the asterisk 
 Title   Read 7 Number (1—50) The integer value of , Every time a value is read , The program prints out the number of *.

 Program analysis   Nothing .

for i in range(3):
    print('*'*int(input('input a number: ')))

 For example 089: Decoding 
 Title   A company uses a public phone to transfer information , Data is a four digit integer , It's encrypted during delivery , The encryption rules are as follows : Add... To each number 5, And divide by sum 10 In place of the number , Exchange the first and the fourth , The second and third place are exchanged .

 Program analysis   Nothing .

n=input()
n = str(n)
a=[]
for i in range(4):
    a.append(int(n[i])+5)
a[0],a[3]=a[3],a[0]
a[1],a[2]=a[2],a[1]
print ("".join('%s' %s for s in a))
 For example 090: List details 
 Title   List usage example item .

 Program analysis   Nothing .

#list  
# New list  
testList=[10086,' China Mobile ',[1,2,4,5]]  
  
# Access list length   
print (len(testList)  )
# To the end of the list 
 print (testList[1:])
# Add elements to the list     
testList.append('i\'m new here!')  
  
print (len(testList)  )
print (testList[-1]  )
# The last element of the pop-up list   
print (testList.pop(1)  )
print (len(testList)  )
print (testList  )
st comprehension  
# There is an introduction later , For a while   
matrix = [[1, 2, 3],  
[4, 5, 6],  
[7, 8, 9]]  
print (matrix  )
print (matrix[1]  )
col2 = [row[1] for row in matrix]#get a  column from a matrix  
print (col2  )
col2even = [row[1] for row in matrix if  row[1] % 2 == 0]#filter odd item  
print (col2even)

 For example 091:time Module 
 Title   Examples of time functions 1.

 Program analysis   Nothing .

if __name__ == '__main__':
    import time
    print (time.ctime(time.time()))
    print (time.asctime(time.localtime(time.time())))
    print (time.asctime(time.gmtime(time.time())))
 For example 092:time Module II
 Title   Examples of time functions 2.

 Program analysis   How to waste time .

if __name__ == '__main__':
    import time
    start = time.time()
    for i in range(3000):
        print(i)
    end = time.time()
 
    print (end - start)

 For example 093:time Module III
 Title   Examples of time functions 3.

 Program analysis   How to waste time .

if __name__ == '__main__':
    import time
    start = time.clock()
    for i in range(100):
        print(i)
    end = time.clock()
    print('different is %6.3f' % (end - start))
 For example 094:time Module IV
 Title   Examples of time functions 4.

 Program analysis   How to waste time .

if __name__ == '__main__':
    import time
    import random
    
    play_it = input('do you want to play it.(\'y\' or \'n\')')
    while play_it == 'y':
        c = input('input a character:\n')
        i = random.randint(0,2**32) % 100
        print ('please input number you guess:\n')
        start = time.clock()
        a = time.time()
        guess = int(input('input your guess:\n'))
        while guess != i:
            if guess > i:
                print('please input a little smaller')
                guess = int(input('input your guess:\n'))
            else:
                print('please input a little bigger')
                guess = int(input('input your guess:\n'))
        end = time.clock()
        b = time.time()
        var = (end - start) / 18.2
        print (var)
        # print 'It took you %6.3 seconds' % time.difftime(b,a))
        if var < 15:
            print ('you are very clever!')
        elif var < 25:
            print ('you are normal!')
        else:
            print ('you are stupid!')
        print ('Congradulations')
        print ('The number you guess is %d' % i)
        play_it = input('do you want to play it.')
 For example 095: Convert time format 
 Title   Convert string date to readable date format .

 Program analysis   Just look at it ,dateutil It's a third party Library .

from dateutil import parser
dt = parser.parse("Aug 28 2015 12:00AM")
print (dt)
 For example 096: Count the number of repetitions 
 Title   Count the number of substrings in a string .

 Program analysis   Nothing .

s1='xuebixuebixuebixuebixuebixuebixuebixue'
s2='xuebi'
print(s1.count(s2))
 For example 097: Disk write 
 Title   Enter some characters from the keyboard , Write them to disk files one by one , Until you enter a  #  Until .

 Program analysis   Nothing .

if __name__ == '__main__':
    from sys import stdout
    filename = input(' Enter the file name :\n')
    fp = open(filename,"w")
    ch = input(' Type the string :\n')
    while ch != '#':
        fp.write(ch)
        stdout.write(ch)
        ch = input('')
    fp.close()
 For example 098: Disk write II
 Title   Enter a string from the keyboard , Convert all lowercase letters to uppercase letters , Then output to a disk file "test" Medium storage .

 Program analysis   Nothing .

if __name__ == '__main__':
    fp = open('test.txt','w')
    string = input('please input a string:\n')
    string = string.upper()
    fp.write(string)
    fp = open('test.txt','r')
    print (fp.read())
    fp.close()
 For example 099: Disk reading and writing 
 Title   There are two disk files A and B, Store one line of letters each , Request to merge the information in these two files ( In alphabetical order ),  Output to a new file C in .

 Program analysis   Nothing .

if __name__ == '__main__':
    import string
    fp = open('test1.txt')
    a = fp.read()
    fp.close()
 
    fp = open('test2.txt')
    b = fp.read()
    fp.close()
 
    fp = open('test3.txt','w')
    l = list(a + b)
    l.sort()
    s = ''
    s = s.join(l)
    fp.write(s)
    fp.close()
 For example 100: Turn to the list 
 Title   List to dictionary .

 Program analysis   Nothing .

i = ['a', 'b']
l = [1, 2]
print (dict(zip(i,l)))

&n

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