逐行比较两个不同的文件，并用第三个文件Python编写差异

Question

我想比较两个文本文件，每个文件有三列。一个文件有999行，另一个文件有757行。我希望不同的242行存储在不同的文件中。我使用随机网络生成器创建了第一个文件（999行）（999行是边，第三列是第一列和第二列之间的权重-源节点和目标节点）。

文件格式-文件1、2

1 3 1
16 36 1

我试过了

Compare two files line by line and generate the difference in another file 和 find difference between two text files with one item per line和http://www.daniweb.com/software-development/python/threads/124932/610058#post610058

都不适合我。

我认为这是一个字符串比较的问题。我想比较一下第一栏和第二栏的数字。如果两者都不同，我想把它写到第三个文件。

任何帮助都将不胜感激！

更新

我在@MK发布评论后发布了以下代码。

f = open("results.txt","w")

for line in file("100rwsnMore.txt"):
    rwsncount += 1
    line = line.split()
    src = line[0]
    dest = line[1]
    for row in file("100rwsnDeleted.txt"):
        row = row.split()
        s = row[0]
        d = row[1]
        if(s != src and d != dest):
             f.write(str(s))
             f.write(' ')
             f.write(str(d))
             f.write('\n')

f.close()

Answer 1

如果您使用的是*nix系统，最好的通用选项是使用：

sort filea fileb | uniq -u

但如果需要使用Python：

您的代码在外部文件的每次迭代中重新打开内部文件。在圈外打开。

使用嵌套循环比循环第一个存储找到的值，然后将第二个值与这些值进行比较效率低。

def build_set(filename):
    # A set stores a collection of unique items.  Both adding items and searching for them
    # are quick, so it's perfect for this application.
    found = set()

    with open(filename) as f:
        for line in f:
            # [:2] gives us the first two elements of the list.
            # Tuples, unlike lists, cannot be changed, which is a requirement for anything
            # being stored in a set.
            found.add(tuple(sorted(line.split()[:2])))

    return found

set_more = build_set('100rwsnMore.txt')
set_del = build_set('100rwsnDeleted.txt')

with open('results.txt', 'w') as out_file:
   # Using with to open files ensures that they are properly closed, even if the code
   # raises an exception.

   for res in (set_more - set_del):
      # The - computes the elements in set_more not in set_del.

      out_file.write(" ".join(res) + "\n")