How can I change the output file name without reading in the whole file?

Question

So, I am using this to replace a text odirx in a file and then writing it out to another file. But I would like the output file name to be sm_0120.txt instead of sm_template2.txt as well.

replacements = {'odirx':'0120'}

with open('/dir/sm_template.txt') as infile, open('/dir/sm_template2.txt', 'w') as outfile:
    for line in infile:
        for src, target in replacements.items():
            line = line.replace(src, target)
        outfile.write(line)

How can I do this?

It could write out the entire file after reading in, but I wanted to do this without reading in the whole file

Related: replacing text in a file with Python

TRIAL

I AM OKAY WITH READING IT IN IF THAT IS MY ONLY CHOICE

replacements = {'odirx':'0120'}

with open('/dir/sm_template.txt') as infile, open('/dir/sm_template2.txt', 'w') as outfile:
        for line in infile:
            for src, target in replacements.items():
                line = line.replace(src, target)
            lines.append(line)
            outfile = os.path.join(os.path.normpath(os.getcwd()+os.sep+"sm_"+os.sep+target+os.extsep+"txt"))

How can I write it out?

use os.rename for changing the file once you save it – Hariom Singh Sep 05 '17 at 23:26 — Hariom Singh, Sep 05 '17 at 23:26
He wants two copies of the file if I understand correctly – jmercouris Sep 05 '17 at 23:45 — jmercouris, Sep 05 '17 at 23:45
@jmercouris Yes! Please see my edit "TRIAL" – maximusdooku Sep 05 '17 at 23:45 — maximusdooku, Sep 05 '17 at 23:45

jmercouris · Answer 1 · 2017-09-05T23:49:30.693

0

Unfortunately you'll have to write a new file since you are modifying it as part of a stream, there is no way around that

to clarify though, there do exist functions for copying files https://stackoverflow.com/a/123212/1699398

edited Sep 05 '17 at 23:49

answered Sep 05 '17 at 23:11

jmercouris

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5
17

score 0 · Answer 2 · answered Sep 05 '17 at 23:29

0

Use os.rename:

os.rename('/dir/sm_template2.txt', '/dir/sm_0120.txt')

answered Sep 05 '17 at 23:29

Hariom Singh

3,512
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How can I change the output file name without reading in the whole file?

2 Answers2