如何计算组合的百分比

Question

我有这个密码生成器，它从包含小写字母、大写字母和数字(不含0(的列表中计算长度为2到6个字符的组合，总共61个字符。

我所需要的只是显示已经创建的组合的百分比(步长为5(。我试图计算所选长度的所有组合，从这个数字计算一个边界值(5%的步长值(，并计算写在文本文件中的每个组合，当组合的计数满足边界值时，打印xxx % completed，但这个代码似乎不起作用。

你知道如何简单地显示百分比吗？

对不起，我的英语不是母语。

谢谢大家！

def pw_gen(characters, length):
"""generate all characters combinations with selected length and export them to a text file"""
# counting number of combinations according to a formula in documentation
k = length
n = len(characters) + k - 1
comb_numb = math.factorial(n)/(math.factorial(n-length)*math.factorial(length))
x = 0
# first value
percent = 5
# step of percent done to display
step = 5
# 'step' % of combinations
boundary_value = comb_numb/(100/step)
try:
# output text file
with open("password_combinations.txt", "a+") as f:
for p in itertools.product(characters, repeat=length):
combination = ''.join(p)
# write each combination and create a new line
f.write(combination + 'n')
x += 1
if boundary_value <= x <= comb_numb:
print("{} % complete".format(percent))
percent += step
boundary_value += comb_numb/(100/step)
elif x > comb_numb:
break

Answer 1

首先，我认为您对组合使用了不正确的公式，因为itertools.product会产生重复的变化，因此正确的公式是n^k(n的k的幂(。

此外，您的百分比计算有点过于复杂。我刚刚修改了您的代码以按预期工作。

import math
import itertools
def pw_gen(characters, length):
"""generate all characters combinations with selected length and export them to a text file"""
k = length
n = len(characters)
comb_numb = n ** k
x = 0
next_percent = 5
percent_step = 5
with open("password_combinations.txt", "a+") as f:
for p in itertools.product(characters, repeat=length):
combination = ''.join(p)
# write each combination and create a new line
f.write(combination + 'n')
x += 1
percent = 100.0 * x / comb_numb
if percent >= next_percent:
print(f"{next_percent} % complete")
while next_percent < percent:
next_percent += percent_step

棘手的部分是while循环，它确保对于非常小的集合(其中一个组合超过step结果的百分比(，一切都能正常工作。

Answer 2

删除了try:，因为您没有使用expect处理任何错误。同样删除了elif:，无论如何都不会满足这个条件。此外，你的comb_numb公式不是正确的，因为你正在生成具有重复的组合。有了这些更改，您的代码就很好了。

import math, iterations, string
def pw_gen(characters, length):
"""generate all characters combinations with selected length and export them to a text file"""
# counting number of combinations according to a formula in documentation
comb_numb = len(characters) ** k
x = 0
# first value
percent = 5
# step of percent done to display
step = 5
# 'step' % of combinations
boundary_value = comb_numb/(100/step)
# output text file
with open("password_combinations.txt", "a+") as f:
for p in itertools.product(characters, repeat=length):
combination = ''.join(p)
# write each combination and create a new line
f.write(combination + 'n')
x += 1
if boundary_value <= x:
print("{} % complete".format(percent))
percent += step
boundary_value += comb_numb/(100/step)
pw_gen(string.ascii_letters, 4)