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分享程序员开发的那些事...
且构网 - 分享程序员编程开发的那些事

使用 Python 对文本文件进行排序

更新时间:2022-12-30 17:03:35

不要对内存中的 1000 万行进行排序.改为分批拆分:

Don't sort 10 million lines in memory. Split this up in batches instead:

  • 运行 100 次 100k 行排序(使用文件作为迭代器,结合 islice() 或类似方法来选择一个批次).写出到别处的单独文件.

  • Run 100 100k line sorts (using the file as an iterator, combined with islice() or similar to pick a batch). Write out to separate files elsewhere.

合并排序后的文件.这是一个合并生成器,您可以传递 100 个打开的文件,它会按排序顺序生成行.逐行写入新文件:

Merge the sorted files. Here is an merge generator that you can pass 100 open files and it'll yield lines in sorted order. Write to a new file line by line:

import operator

def mergeiter(*iterables, **kwargs):
    """Given a set of sorted iterables, yield the next value in merged order

    Takes an optional `key` callable to compare values by.
    """
    iterables = [iter(it) for it in iterables]
    iterables = {i: [next(it), i, it] for i, it in enumerate(iterables)}
    if 'key' not in kwargs:
        key = operator.itemgetter(0)
    else:
        key = lambda item, key=kwargs['key']: key(item[0])

    while True:
        value, i, it = min(iterables.values(), key=key)
        yield value
        try:
            iterables[i][0] = next(it)
        except StopIteration:
            del iterables[i]
            if not iterables:
                raise