Python Learning (7)

Exercise 7: Judging whether a number is prime

import mathdef is_prime(num):    if num==1:        return False    if num==2:        return True    else:        for i in range(2,int(math.sqrt(num))+1):            if num%i == 0:                return False        return Trueprint(is_prime(13))print(is_prime(12))print(is_prime(2))习题8：求100以内的素数和result = 0for i in range(100):    if is_prime(i):        result += iprint(result)

Exercise 9: Use the For method to find the sum of the odd numbers within 100

#encoding=utf-8import mathresult = 0for i in range(101):    if i%2 == 1:        result += iprint(result)

Exercise 10: The user enters multiple numbers, sums up when an even number is entered, enters odd, does not sum, enters. (one point) end sum, print sum result

sum = 0while True:    number = input("please input the number: ")    if number == ".":        break    else:        number = int(number)        if number%2 ==0:            sum += numberprint(sum)      

Exercise 11: Nested loop output 10-50 all digits with 1-5 in each digit:
Method 1: Number and 10, determine if greater than 0 and less than or equal to 5
Method 2: Convert the number to STR and take your characters to determine if the character is within 1-5.
Method 3: Stitching the digits

Method 1:

#encoding=utf-8import mathfor i in range(10,51):    if i%10 >=1 and i%10 <= 5:        print(i)

Method 2:

for i in range(10,51):    if str(i)[1] in "12345":        print(i)

Method 3:

for i in "1234":    for j in "12345":        print(int(i+j))

Exit the Double loop:

方式1：try--excepttry:    for i in range(5):        for j in range(5):            if i==3 and j ==3:                raiseexcept:    print(1)pass

Mode 2: Return of function implementation

def fun():    for i in range(5):        for j in range(5):            print(i,j)            if i==3 and j ==3:                return Truefun()

Mode 3: Multi-layer break

for i in range(5):    for j in range(5):        for k in range(5):            if i == j == k == 3:                break            else:                print (i, ‘----‘, j, ‘----‘, k)        else: continue        break    else: continue    break

Python Learning (7)