Answer to Question #315334 in Python for Michael

Question

 Write a python function Read_Prime(fname, list) which takes a list of numbers as an input, use this number to write them in a file "primes.txt" . The function then read the file and return a list containing only prime numbers as shown in the example. Also, write the exception handling code to show the proper message.

 

Example-1

Example-2

Example-2

Input:

primes.txt

[1,2,3,4,5,6,7]

 

Output:

[1,2,3,5,7]

Input:

primes.txt

[3,6,5,13,18,21]

 

Output:

[3,5,13]

Input:

primes.txt

[2,4,6,8,10]

 

Output:

[2]

 

Answer 1

import json

def Read_Prime(fname, list):
    array=[]
    rez =[]
    isdig = 0
    for number in list:
        if not number.isdigit():
            isdig = 1
            print(f'{number} is not number')
            return
        else:
            array.append(int(number))
    if isdig == 0:
        with open(fname, 'w') as fw:
            json.dump(array, fw)        #  write list
        with open(fname, 'r') as fr:
            lst = json.load(fr)         #  read list    
        for i in range(len(lst)):
            isprime = 1
            if lst[i] > 1:
                for num in range (2, lst[i]):
                    if lst[i] % num == 0:
                        isprime = 0
                if isprime == 1:
                    rez.append(int(lst[i]))
            else:
                 rez.append(int(lst[i]))                 
    if len(rez) == 0:
        print('No prime numbers')
    return rez

print('Enter filename: ', end='')
filename = input()
print('Enter list: ', end='')
a = input().split()
print(Read_Prime(filename, a))