python - Code for coyping specific lines from multiple files to a single file (and removing part of the copied lines) -

first of all, new this. i've been reading on tutorials on past days, i've hit wall want achieve.

to give long version: have multiple files in directory, of contain information in lines (23-26). now, code have find , open files (naming pattern: *.tag) , copy lines 23-26 new single file. (and add new line after each new entry...). optionally remove specific part each line not need:

c12b2

-> before c12b2 (or similar) need removed.

thus far have managed copy lines single file new file, rest still eludes me: (no idea how formatting works here)

f = open('2.tag')       n = open('output.txt', 'w')  i, text in enumerate(f):      if >= 23 , < 27:          n.write(text)      else:          pass 

could give me advice ? not need complete code answer, however, tutorials don't skip explanations seem hard come by.

without importing os:

#!/usr/bin/env python3 import os # set directory, outfile , tag below dr = "/path/to/directory"; out = "/path/to/newfile"; tag = ".txt"  f in [f f in os.listdir(dr) if f.endswith(".txt")]:     open(out, "+a").write(("").join([l l in open(dr+"/"+f).readlines()[22:25]])+"\n") 

what does

it describe, it:

• collects defined region of lines files (that is: of defined extension) in directory
• pastes sections new file, separated new line

explanation

[f f in os.listdir(dr) if f.endswith(".tag")] 

lists files of specific extension in directory,

[l l in open(dr+"/"+f).readlines()[22:25]] 

reads selected lines of file

open(out, "+a").write() 

writes output file, creates if not exist.

how use

• copy script empty file, save collect_lines.py
• set in head section directory files, path new file , extension

• run command:

  python3 /path/to/collect_lines.py 

the verbose version, explanation

if "decompress" code above, happens:

#!/usr/bin/env python3 import os #--- set path directory, new file , tag below dr = "/path/to/directory"; out = "/path/to/newfile"; tag = ".txt" #---  files = os.listdir(dr) f in files:     if f.endswith(tag):         # read file list of lines         content = open(dr+"/"+f).readlines()         # first item in list = index 0, line 23 index 22         needed_lines = content[22:25]         # convert list string, add new line         string_topaste = ("").join(needed_lines)+"\n"         # add lines new file, create file if necessary         open(out, "+a").write(string_topaste)