Python - 将行范围（由值确定）从文本文件复制到新文本文件

Question

I'm trying to write a script that can find the start and end rows to copy from one text file to another. My code works (sort of) but with a few issues...

• I found the start (#04) but I can't figure out how to find the end row, so I am currently just adding 100 rows
• The output is one line with "\n"s instead of page breaks.

As a new coder, I am sure there is a more eloquent and effective way to program this.

Any advice will be greatly appreciated.

• GM.net

from tkinter.filedialog import askopenfilename

#01 ask name of read file and open it
filename = askopenfilename()
fp = open(filename, 'r')

#02 open write file (would be good to prompt for name)
outf = open('/Users/gmonet/Desktop/TechSupport/output_file3.txt', 'w')

#03 read the read file
lines = fp.readlines()

#04 find the string that will determine the start range to copy
for row in lines:
    word = 'Tech Support SubSection =  "service usage"'
    if  row.find(word) != -1:
        row2start = lines.index(row)

#05 copy 100 lines to the write file, starting at row2start
for line in lines:
    outf.write(str(lines[row2start:row2start+100]).splitlines())

#06 close both files
fp.close()
outf.close()

When I run the code, it returns one very long line with many "\n"'s. I also haven't specified the end of the range by value (just capturing 200 lines.

Answer 1

Are you looking for something like this?

end = len(lines)
for out_l in lines[row2start:end+1]:
    outf.write(out_l)