大家好，我现在遇到了一个特别头疼的问题：用Python生成字符组合时总是触发内存限制错误，进程会中途直接崩溃。我有三段实现类似功能的代码，在模拟器上测试时，哪怕是生成4字符长度的组合，进程跑到大概1/8的进度就直接挂了。我已经把Python升级到64位版本，还调整了电脑的内存设置（设为32000到40000字节，我记得是这个单位），甚至在考虑要不要用任务管理器给Python进程提优先级，但问题还是没解决。

所有帮助我都万分感激！

第一段代码：递归打印字符组合（进程1/8进度崩溃） #

这段代码的功能是打印指定字符集的所有组合，但每次运行到大约1/8的进度就会自行终止：

stuff = ["~","!","@","#","$","%","^","&","*","(",")","_","+","`","1","2","3","4","5","6","7","8","9","0","-","=","Q","W","E","R","T","Y","U","I","O","P","{","}","|","q","w","e","r","t","y","u","i","o","p","[","]","Backslash","A","S","D","F","G","H","J","K","L",":",'"',"a","s","d","f","g","h","j","k",";","'","Z","X","C","V","B","N","M","<",">","?","z","x","c","v","b","n","m",",",".","/"," "]
len=len(stuff)
def generate(stuff,i,s,len):
    if (i == 0):
        print(s)
        return
    for j in range(0,len):
        appended = s + stuff[j]
        generate(stuff,i-1,appended,len)
    return
def crack(stuff,len):
    for i in range(18,19):
        generate(stuff,i,"",len)
crack(stuff,len)

第二段代码：生成组合写入文件（3字符长度时1/8进度崩溃） #

这段代码尝试把生成的组合以类表格格式写入文件，但同样在运行到1/8左右时崩溃。我有两个疑问：

• 怎么才能生成更大的输出文件？
• 有没有办法给这个Python进程分配更多内存？

characters = ["~","!","@","#","$","%","^","&","*","(",")","_","+","`","1","2","3","4","5","6","7","8","9","0","-","=","Q","W","E","R","T","Y","U","I","O","P","{","}","|","q","w","e","r","t","y","u","i","o","p","[","]",'"BackslashCharacter"',"A","S","D","F","G","H","J","K","L",":",'"',"a","s","d","f","g","h","j","k",";","'","Z","X","C","V","B","N","M","<",">","?","z","x","c","v","b","n","m",",",".","/"," "]
import itertools
combinations = list(itertools.product(characters,repeat=3))
testfileofcombinationsname = "testfile.txt"
size_in_bytes=(1024*1024)
filename = "combinationsfile"
import os
def testtxtcombinationsfile(testfileofcombinationsname, size_in_bytes):
    with open({testfileofcombinationsname}, 'wb') as combinationsfile:
        {filename}.seek(size_in_bytes - 1)
        {filename}.write(b'\0')
with open(testfileofcombinationsname, 'a') as combinationsfile:
    for row in combinations:
        line = "  ".join(row)
        combinationsfile.write(line + '\n')
print('A "said" table has been appended and written to testfile.txt!')

第三段代码：写入文件时的seek异常问题 #

这段代码同样是生成组合写入文件，但我设置了seek(4)，结果模拟器显示文件超过4KB，还曾经生成过全是红色高亮圆点的文件。我有几个疑问：

• 为什么seek设置这么小，最终生成的文件却这么大？
• 怎么正确使用seek来创建指定大小的文件（比如8KB）？
• 有没有优化方案，能让这段代码更省内存、运行更稳定？

characters = ["~","!","@","#","$","%","^","&","*","(",")","_","+","`","1","2","3","4","5","6","7","8","9","0","-","=","Q","W","E","R","T","Y","U","I","O","P","{","}","|","q","w","e","r","t","y","u","i","o","p","[","]",'"BackslashCharacter"',"A","S","D","F","G","H","J","K","L",":",'"',"a","s","d","f","g","h","j","k",";","'","Z","X","C","V","B","N","M","<",">","?","z","x","c","v","b","n","m",",",".","/"," "]
import itertools
combinations = list(itertools.product(characters,repeat=3))
testfileofcombinationsname = "testfile.txt"
combinationsfile = open("testfile.txt", "wb")
combinationsfile.seek(4)
combinationsfile.write(b"\0")
with open(testfileofcombinationsname, 'a') as combinationsfile:
    for row in combinations:
        line = "  ".join(row)
        combinationsfile.write(line + '\n')

备注：内容来源于stack exchange，提问作者Python Learner