Question

前言：我意识到这段代码正在寻找斐波那契数字，而不是素数。

问题：由于某种原因，savework()功能无效。当我运行python交互式会话并重复运行get_next_prime()时，它会在该会话中按预期生成序列中的下一个数字。但是，当我关闭会话并打开一个新会话时，它应该记住之前的条目（因为pickle.dump等），但不是。应每次运行时调用pickle字节文件。为什么不呢？

我是初学者：请保持温柔。谢谢！

代码：

# Write a function which, for each run, returns the smallest positive prime number larger than the one returned previously. 


""" Find and maintain a cumulative list of Prime numbers """ 


import pickle 

import atexit 


try: 
with open("dict_of_primes","rb") as file1, \
    open("last_prime_index_found","rb") as file2: 
        dict_of_primes = pickle.load(file1) 
        last_prime_index_found = pickle.load(file2) 

# Start fresh if either file could not be found 
except FileNotFoundError: 
    dict_of_primes = {} 
    last_prime_index_found = -1 

def get_next_prime(): 
    """ Get the next prime number """ 
    global last_prime_index_found 
    n = last_prime_index_found + 1 

    if n in [0,1]: 
        dict_of_primes[n] = n 

    else:
        dict_of_primes[n] = \
            dict_of_primes[n-1] +\
            dict_of_primes[n-2] 

    last_prime_index_found = n 
    return dict_of_primes[n] 

def save_work(): 
    """ Saves data for next session """ 
    with open("dict_of_primes","wb") as file1, \
        open("last_prime_index_found","wb") as file2:
            pickle.dump(dict_of_primes,file1) 
            pickle.dump(last_prime_index_found,file2)

# This will insure that save_work() is called 
# when you end your session     

atexit.register(save_work)

Python交互式会话：

`C:\Users\Fiona Murphey\Desktop>python`

`Python 3.5.2 (v3.5.2:4def2a2901a5, Jun 25 2016, 22:18:55) [MSC v.1900 64 bit (AMD64)] on win32`

`Type "help", "copyright", "credits" or "license" for more information.`

`>>> from lastprime import *`

`>>> get_next_prime()`

`0`

`>>> get_next_prime()`

`1`

`>>> get_next_prime()`

`1`

`>>> get_next_prime()`

`2`

`>>> get_next_prime()`

`3`

`>>> get_next_prime()`

`5`

`>>> save_work()`

`>>> exit()`

在终端： -

C:\Users\Fiona Murphey\Desktop>python
    Python 3.5.2 (v3.5.2:4def2a2901a5, Jun 25 2016, 22:18:55) [MSC v.1900 64 bit (AMD64)] on win32

    Type "help", "copyright", "credits" or "license" for more information.
>>> from lastprime import *

>>> get_next_prime()

0

>>>

python pickle.dump没有激活？

0 个答案: