从列表中随机选择50个项目写入文件

问题:从列表中随机选择50个项目写入文件

到目前为止,我已经弄清楚了如何导入文件,创建新文件以及使列表随机化。

我在从列表中随机选择50个项目以写入文件时遇到麻烦吗?

def randomizer(input,output1='random_1.txt',output2='random_2.txt',output3='random_3.txt',output4='random_total.txt'):

#Input file 
    query=open(input,'r').read().split()
    dir,file=os.path.split(input)

    temp1 = os.path.join(dir,output1)
    temp2 = os.path.join(dir,output2)
    temp3 = os.path.join(dir,output3)
    temp4 = os.path.join(dir,output4)


    out_file4=open(temp4,'w')

    random.shuffle(query)

    for item in query:
        out_file4.write(item+'\n')   

因此,如果总随机文件为

example:

random_total = ['9','2','3','1','5','6','8','7','0','4']

我想要3个文件(out_file1 | 2 | 3),其中第一个随机集为3,第二个随机集为3,第三个随机集为3(对于此示例,但我要创建的文件应该有50个)

random_1 = ['9','2','3']
random_2 = ['1','5','6']
random_3 = ['8','7','0']

因此,不会包含最后一个“ 4”,这很好。

如何从随机选择的列表中选择50?

更好的是,如何从原始列表中随机选择50个?

So far I have figured out how to import the file, create new files, and randomize the list.

I’m having trouble selecting only 50 items from the list randomly to write to a file?

def randomizer(input,output1='random_1.txt',output2='random_2.txt',output3='random_3.txt',output4='random_total.txt'):

#Input file 
    query=open(input,'r').read().split()
    dir,file=os.path.split(input)

    temp1 = os.path.join(dir,output1)
    temp2 = os.path.join(dir,output2)
    temp3 = os.path.join(dir,output3)
    temp4 = os.path.join(dir,output4)


    out_file4=open(temp4,'w')

    random.shuffle(query)

    for item in query:
        out_file4.write(item+'\n')   

So if the total randomization file was

example:

random_total = ['9','2','3','1','5','6','8','7','0','4']

I would want 3 files (out_file1|2|3) with the first random set of 3, second random set of 3, and third random set of 3 (for this example, but the one I want to create should have 50)

random_1 = ['9','2','3']
random_2 = ['1','5','6']
random_3 = ['8','7','0']

So the last ‘4’ will not be included which is fine.

How can I select 50 from the list that I randomized ?

Even better, how could I select 50 at random from the original list ?


回答 0

如果列表按随机顺序排列,则可以只取前50个。

否则,使用

import random
random.sample(the_list, 50)

random.sample 帮助文字:

sample(self, population, k) method of random.Random instance
    Chooses k unique random elements from a population sequence.

    Returns a new list containing elements from the population while
    leaving the original population unchanged.  The resulting list is
    in selection order so that all sub-slices will also be valid random
    samples.  This allows raffle winners (the sample) to be partitioned
    into grand prize and second place winners (the subslices).

    Members of the population need not be hashable or unique.  If the
    population contains repeats, then each occurrence is a possible
    selection in the sample.

    To choose a sample in a range of integers, use xrange as an argument.
    This is especially fast and space efficient for sampling from a
    large population:   sample(xrange(10000000), 60)

If the list is in random order, you can just take the first 50.

Otherwise, use

import random
random.sample(the_list, 50)

random.sample help text:

sample(self, population, k) method of random.Random instance
    Chooses k unique random elements from a population sequence.

    Returns a new list containing elements from the population while
    leaving the original population unchanged.  The resulting list is
    in selection order so that all sub-slices will also be valid random
    samples.  This allows raffle winners (the sample) to be partitioned
    into grand prize and second place winners (the subslices).

    Members of the population need not be hashable or unique.  If the
    population contains repeats, then each occurrence is a possible
    selection in the sample.

    To choose a sample in a range of integers, use xrange as an argument.
    This is especially fast and space efficient for sampling from a
    large population:   sample(xrange(10000000), 60)

回答 1

选择随机项目的一种简单方法是先随机播放然后切片。

import random
a = [1,2,3,4,5,6,7,8,9]
random.shuffle(a)
print a[:4] # prints 4 random variables

One easy way to select random items is to shuffle then slice.

import random
a = [1,2,3,4,5,6,7,8,9]
random.shuffle(a)
print a[:4] # prints 4 random variables

回答 2

我认为random.choice()是更好的选择。

import numpy as np

mylist = [13,23,14,52,6,23]

np.random.choice(mylist, 3, replace=False)

该函数从列表中返回3个随机选择的值的数组

I think random.choice() is a better option.

import numpy as np

mylist = [13,23,14,52,6,23]

np.random.choice(mylist, 3, replace=False)

the function returns an array of 3 randomly chosen values from the list


回答 3

假设您的列表包含100个元素,并且您想随机选择50个元素。以下是要遵循的步骤:

  1. 导入库
  2. 为随机数生成器创建种子,我将其放在2
  3. 准备一个数字列表,从中随机抽取
  4. 从数字列表中进行随机选择

码:

from random import seed
from random import choice

seed(2)
numbers = [i for i in range(100)]

print(numbers)

for _ in range(50):
    selection = choice(numbers)
    print(selection)

Say your list has 100 elements and you want to pick 50 of them in a random way. Here are the steps to follow:

  1. Import the libraries
  2. Create the seed for random number generator, I have put it at 2
  3. Prepare a list of numbers from which to pick up in a random way
  4. Make the random choices from the numbers list

Code:

from random import seed
from random import choice

seed(2)
numbers = [i for i in range(100)]

print(numbers)

for _ in range(50):
    selection = choice(numbers)
    print(selection)