合并2个文件以创建1个文件作为输出

Question

I got 2 documents which look likes: First:

port2
port4
port10
etc.

Second:

port1
some stuff
about the port
I do not need
!
port2
some stuff
about the port
I really need
!
some generic stuff which is completely useless
!
port3
some stuff
about the port
I do not need
!
port4
some stuff
about the port
I really need
!
etc

Now, what I want is to create a loop that for each line in the first document we'll go through the second document and create a new file which contains all the data I need ("port2" until "!", "port4" until "!" etc)

What I got so far:

def access():
with open ("D:/portlist.txt") as f1, open ("D:/config.txt") as f2:
    match = False
    for line in f1:
        newConfig = open ("D:/portconfig.test.txt", "a")
        interface = line
        for line2 in f2:
            if re.match(interface, line2):
                newConfig.write(line2)
                print(line2)
                match = True
            elif re.match("!", line2):
                match = False   
            elif match:
                newConfig.write(line2)
        newConfig.close()   
access()

Problem is that the script stops after returning all about port2. It seems like the script doesn't return to the first loop to continue the process. Any ideas?

Answer 1

Your problem stems from the fact that once a file is read to the end, it doesn't automatically seek back to the first point. Since you're looping over the second file for each of the values you search, you either need to seek back via f2.seek(0) , or simply read the file's content in memory only once and then loop on that.

About your code a quick (and dirty) solution exploits the fact that you have block separators ( ! ):

with open(...) as f1, open(...) as f2:
  section_names_to_keep = f1.read().splitlines()
  config_content = f2.read()

config_blocks = config_content.split('!\n')
blocks_to_keep = [ bl for bl in config_blocks if bl.splitlines()[0] in section_names_t_keep ]

with open('your_output_file.txt', 'a') as fp:
  fp.write('!\n'.join(blocks_to_keep))

Note: You weren't too clear on the expected output format, so I assume it should look like config.txt . I write to the output file all at once (first I generate the output content in memory with '!\\n'.join(blocks_to_keep) and then it gets written out). If (as I'm assuming) your data is small, this won't be an issue. If that's not the case, just loop over blocks_to_keep and write out block by block.

Small code explanation:

In the first block I simply load the content of both files. Since for the first file we're interested in each line, I already split it over the lines.

In the second block, I split the config over the block separator !\\n and then I filter the list of blocks keeping only those blocks whose first line is in the list we got from the first file.

The third block is just output.