Python Brute Force algorithm

user_1535096 0
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I need to generate every possible combination from a given charset to a given range. Like, 

charset=list(map(str,"abcdefghijklmnopqrstuvwxyz"))
range=10

And the out put should be,

[a,b,c,d..................,zzzzzzzzzy,zzzzzzzzzz]

I know I can do this using already in use libraries.But I need to know how they really works.If anyone can give me a commented code of this kind of algorithm in Python or any programming language readable,I would be very grateful.

brute-force algorithm python
10 Answers

If you really want a bruteforce algorithm, don't save any big list in the memory of your computer, unless you want a slow algorithm that crashes with a MemoryError.

You could try to use itertools.product like this :

from string import ascii_lowercase
from itertools import product

charset = ascii_lowercase  # abcdefghijklmnopqrstuvwxyz
maxrange = 10


def solve_password(password, maxrange):
    for i in range(maxrange+1):
        for attempt in product(charset, repeat=i):
            if ''.join(attempt) == password:
                return ''.join(attempt)


solved = solve_password('solve', maxrange)  # This worked for me in 2.51 sec

itertools.product(*iterables) returns the cartesian products of the iterables you entered.

[i for i in product('bar', (42,))] returns e.g. [('b', 42), ('a', 42), ('r', 42)]

The repeat parameter allows you to make exactly what you asked :

[i for i in product('abc', repeat=2)]

Returns

[('a', 'a'),
 ('a', 'b'),
 ('a', 'c'),
 ('b', 'a'),
 ('b', 'b'),
 ('b', 'c'),
 ('c', 'a'),
 ('c', 'b'),
 ('c', 'c')]

Note:

You wanted a brute-force algorithm so I gave it to you. Now, it is a very long method when the password starts to get bigger because it grows exponentially (it took 62 sec to find the word 'solved').

user_83996560

Simple solution using the itertools and string modules

# modules to easily set characters and iterate over them
import itertools, string 

# character limit so you don't run out of ram
maxChar = int(input('Character limit for password: '))  

# file to save output to, so you can look over the output without using so much ram
output_file = open('insert filepath here', 'a+') 

# this is the part that actually iterates over the valid characters, and stops at the 
# character limit.
x = list(map(''.join, itertools.permutations(string.ascii_lowercase, maxChar))) 

# writes the output of the above line to a file 
output_file.write(str(x)) 

# saves the output to the file and closes it to preserve ram
output_file.close()

I piped the output to a file to save ram, and used the input function so you can set the character limit to something like "hiiworld". Below is the same script but with a more fluid character set using letters, numbers, symbols, and spaces.

import itertools, string

maxChar = int(input('Character limit for password: '))
output_file = open('insert filepath here', 'a+')

x = list(map(''.join, itertools.permutations(string.printable, maxChar)))
x.write(str(x))
x.close()
user_96942900
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