Question

我正在尝试从包含芬兰语文本的500mb文本文件中创建排名单词列表的csv文件。该脚本可以用小文件完成我想要的操作，但不适用于500mb的野兽。

我是使用Python的完整入门者，所以如果它很草率，请原谅我。从四周看，我认为可能必须逐行处理文件。

with open(...) as f:
    for line in f:
    # Do something with 'line'

我将不胜感激，加油！我的代码如下：

#load text
filename = 'finnish_text.txt'
file = open(filename, 'r')
text = file.read()
file.close()

#lowercase and split words by white space
lowercase = text.lower()
words = lowercase.split()

# remove punctuation from each word
import string
table = str.maketrans('', '', string.punctuation)
stripped = [w.translate(table) for w in words]

# ranked word count specify return amount here
from collections import Counter
Counter = Counter(stripped)
most_occur = Counter.most_common(100)

# export csv file
import csv
with open('word_rank.csv', 'w', newline='') as csvfile:
    writer = csv.writer(csvfile, delimiter=',')
    for x in most_occur:
        writer.writerow(x)

编辑：我最终使用了@Bharel（他的传说）的第二个解决方案，该解决方案在他的评论中给出。由于编码问题，我不得不更改几行。

with open(filename, 'r', encoding='Latin-1', errors='replace') as file:

with open('word_rank.csv', 'w', newline='', errors='replace') as csvfile:

Answer 1

将所有内容切换到生成器，它应该可以工作：

#load text
filename = 'finnish_text.txt'
# Auto-close when done
with open(filename, 'r') as file:

    #lowercase and split words by white space
    word_iterables =(text.lower().split() for line in file)

    # remove punctuation from each word
    import string
    table = str.maketrans('', '', string.punctuation)

    stripped = (w.translate(table) for it in word_iterables for w in it)

    # ranked word count specify return amount here
    from collections import Counter
    counter = Counter(stripped)

most_occur = counter.most_common(100)

# export csv file
import csv
with open('word_rank.csv', 'w', newline='') as csvfile:
    writer = csv.writer(csvfile, delimiter=',')
    for x in most_occur:
        writer.writerow(x)

通过使用生成器（用括号代替方括号），所有单词都被延迟处理，而不是一次全部加载到内存中。

如果您想以最有效的方式，我已经写了一个自我挑战：

import itertools
import operator

#load text
filename = 'finnish_text.txt'
# Auto-close when done
with open(filename, 'r') as file:

    # Lowercase the lines
    lower_lines = map(str.lower, file)

    # Split the words in each line - will return [[word, word], [word, word]]
    word_iterables = map(str.split, lower_lines)

    # Combine the iterables:
    # i.e. [[word, word], [word, word]] -> [word, word, word, word]
    words = itertools.chain.from_iterable(word_iterables)

    import string
    table = str.maketrans('', '', string.punctuation)

    # remove punctuation from each word
    stripped = map(operator.methodcaller("translate", table), words)

    # ranked word count specify return amount here
    from collections import Counter
    counter = Counter(stripped)

most_occur = counter.most_common(100)

# export csv file
import csv
with open('word_rank.csv', 'w', newline='') as csvfile:
    writer = csv.writer(csvfile, delimiter=',')
    for x in most_occur:
        writer.writerow(x)

它充分利用了用C语言编写的生成器（map和itertools）。

对单词进行计数和排名时，带有大型.txt文件Python的MemoryError

1 个答案: