Python：比较相同随机行的两个文本文件

Question

I got a file wordlist.txt with 100 random words in it, each on a separate line. I currently use the following code to grab 12 random words from this file. To avoid picking exactly the same 12 words i want to builtin an extra check. The 12 random words are written to output.txt. How can i make my script compare the 12 random words (in the same order) with the 12 random words i have in output.txt (in 1 line)?

I currently use the following to read 12 random words from wordlist.txt and write them to output.txt:

teller = 0

while True:
    teller += 1

    #Choose 12 random words and write to textfile
    print "\nRound",teller
    f1=open('output.txt', 'w+')
    count = 0
    while (count<12):
        f1.write(random.choice([x.rstrip() for x in open('wordlist.txt')])+ " ")
        count += 1
    f1.close()

Answer 1

Instead of random.choice() , read all words into a list and use random.sample() :

with open('wordlist.txt') as wlist:
    words = [w.strip() for w in wlist]
with open('output.txt', 'w') as output:
    for word in random.sample(words, 12):
        output.write(word + '\n')

random.sample() is guaranteed to pick 12 different words from your input list.

Because your wordlist is small (just 100 words), reading them all into a list in memory is more than fine.

If your input file is larger (megabytes to gigabytes), you may want to move to an algorithm that can pick a uniform sample out of any iterable regardless of size, only requiring memory for the output sample size.

If you need to find 12 random words that are not yet present in output.txt from a previous run , you need to read those into a set first:

with open('wordlist.txt') as wlist:
    words = [w.strip() for w in wlist]

with open('output.txt', 'r') as output:
    seen = {w.strip() for w in output}

with open('output.txt', 'a') as output:
    count = 0
    while count < 12:
        new_word = random.choice(words)
        if new_word in seen:
            words.remove(new_word)
            continue
        seen.add(new_word)
        output.write(new_word + '\n')
        count += 1

Here, I open the output.txt file with 'a' for appending instead, to add the new 12 words we had not yet seen before.