Primality quiz

primequiz.py

#!/usr/bin/env python3
# Primality quiz
# Use the commandline argument "p" to show the list
#
# http://sekika.github.io/2016/12/13/Primality/

### Parameters

rep=10 # Numbers of questions

# Control the numbers for questions
# The numbers from first to last, excluding obvious numbers will be shown.
# Obvious numbers include
# (1) Multiple of 2 and 5
# (2) Multiple of 3 (when three=True) 
#       or Numbers where all digits are multiple of 3 (when three=False)
# (3) Numbers in the obvious list

first=29 # Smallest number
last=400 # Largest number
three=False # Make multiple of 3 as obvious
obvious=[7,11,13,21,27,49,77,81,777] # Obvious numbers

########################
import math, random, sys

# Sieve of Eratosthenes; divisor[n] is the minimum divisor
divisor = [i for i in range(0,last+1)]
lastprime=1
for prime in divisor:
    if prime > math.sqrt(last): break
    if prime <= lastprime: continue
    lastprime=prime
    for non_prime in range(2 * prime, last+1, prime):
    	divisor[non_prime] = min(prime, divisor[non_prime])

# factorize(n) shows factorization
def factorize(n):
    n = int(n)
    if n == divisor[n]:
        return str(n)
    else:
        return str(divisor[n])+' * '+factorize(n/divisor[n])

# Prepare primes and nonprimes for questions
prime=[]
nonprime=[]
for n in range(first, last+1):
    if three:
        modthree=n % 3
    else:
        modthree=sum([int(c)%3 for c in str(n)]) # All the digits are multiple of 3?
    if (n % 2)*(n % 5)*modthree != 0 and not n in obvious:
        if n==divisor[n]:
            prime.append(n)
        else:
            nonprime.append(n)

# Read command line argument
if len(sys.argv) > 1:
    arg = sys.argv[1]
else:
    arg = ""

##### Print mode (command line argument = "p")
if arg == "p":
    print ('List of primes')
    print (prime)
    print ('List of composite numbers')
    for n in nonprime:
        print (n, '=', factorize(n))
    sys.exit()

##### Primality quiz
# Prepare the questions
while len(prime)<rep:
    prime.extend(prime)
random.shuffle(prime)
while len(nonprime)<rep:
    nonprime.extend(nonprime)
random.shuffle(nonprime)
question=prime[:rep]
question.extend(nonprime[:rep])
random.shuffle(question)
question=question[:rep]

# Main loop
print (rep, 'questions for primality.')
print (question)
for n in question:
    key=input(str(n)+' is prime? Type return to show the answer. ')
    if n==divisor[n]:
        print ('Prime!')
    else:
        print ('Composite.',n, '=', factorize(n))

素数判定ゲーム
http://sekika.github.io/2016/12/13/Primality/