## Python 100 cases

python cases

``` 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:
elif points<60:
else:
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:
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:
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)
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 is_empty(self):
return self.get_len() == 0
def get_len(self):
length = 0
while temp is not None:
length += 1
temp = temp.next
return length
def append(self, node):
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:
return
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
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
if head is None and head.next is None:
while cur is not None:
temp = cur.next
cur.next = pre
pre = cur
cur = temp
return pre
init_data = []
while head is not None:
return init_data
if __name__=='__main__':
for i in range(10):
node=Node(i)
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 is_empty(self):
return self.get_len() == 0
def get_len(self):
length = 0
while temp is not None:
length += 1
temp = temp.next
return length
def append(self, node):
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:
return
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
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
if head is None and head.next is None:
while cur is not None:
temp = cur.next
cur.next = pre
pre = cur
cur = temp
return pre
init_data = []
while head is not None:
return init_data
if __name__=='__main__':
for i in range(10):
node=Node(i)
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 ('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')
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')
fp.close()

fp = open('test2.txt')
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)))```

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