代码如下：
# 质数判断函数
def is_prime(num): if num < 2: return False elif num == 2 or num == 3: return True else: for i in range(2, int(num**0.5) + 1): if num % i == 0: return False return True # 质因数分解函数
def prime_factorize(num): if num < 2: # 非质数亦非合数
print('"%s" have no prime factor.' % num) return 0 if is_prime(num): # 质数
print('"%s" is prime number!' % num) return 0 else: # 合数
pri_fac_list = [] # 用于保存质因数
while 1: if is_prime(num): pri_fac_list.append(num) break
for i in range(2, num//2 + 1): if is_prime(i) and num % i == 0: # i既是质数又是因数
pri_fac_list.append(i) num = num // i # print('TEST:num = %s' % num)
break # 跳出for循环
print(pri_fac_list) if __name__ == '__main__': global n try: n = int(input('Enter a number:').strip()) # 输入待分解的数
except ValueError: print('Error! Please input a number.') # 异常处理
exit(1) prime_factorize(n)
注意：
若不用 “global n” 将n声明为全局变量，Pycharm将在 “prime_factorize(n)” 处提示警告：
Name 'n' can be not defined less... (Ctrl+F1)
This inspection warns about local variables referenced before assignment.
即赋值前引用局部变量。
