Reading and writing to file

Question

with open('C:\Users\ehwe\Desktop\INPUT_DS_FILE.txt') as old, open('C:\Users\ehwe\Desktop\OUTPUT_DS_FILE.txt', 'w') as new:
        for line in old:
            if re.search('trim\(\w+\)',line) == None:
                new.write(line)
            else:
                new_line = re.sub(r"trim\((\w+)\)", r"TRIM (TRIM (CHR (09) FROM \1))", line)
                new.write (new_line)

This chunk of code reads line from old file and writes it to a new one. It makes certain modifications according to a pattern.

Problem is - I am not able to run the code - the compiler keeps saying SyntaxError: invalid syntax and highlights the comma in the very first line.

Little help please?

P.S.

the code below works fine (in case someone points out that slashes might go wrong)

with open('C:\Users\ehwe\Desktop\INPUT_DS_FILE.txt') as old:
    for line in old:
        if re.search('trim\(\w+\)',line) != None:
            print 'Y'

The slashses ARE a problem. It's possible the interpreter get's it wrong about the position of the error. Try fixing the slases, and see if the error changes. — user590028, Feb 21 '14 at 11:15
http://stackoverflow.com/questions/4617034/python-open-multiple-files-using-with-open — Jayanth Koushik, Feb 21 '14 at 11:16

score 0 · Answer 1 · answered Feb 21 '14 at 11:11

0

You need to escape the backslashes in your open statement

with open('C:\\Users\\ehwe\\Desktop\\INPUT_DS_FILE.txt') as old, open('C:\\Users\\ehwe\\Desktop\\OUTPUT_DS_FILE.txt', 'w') as new:
...

Optionally, you can always use forward slashes, and avoid the backslash issue (fyi -- windows fully understands and accepts forward slashes), eg:

with open('C:/Users/ehwe/Desktop/INPUT_DS_FILE.txt') as old, open('C:/Users/ehwe/Desktop/OUTPUT_DS_FILE.txt', 'w') as new:
...

answered Feb 21 '14 at 11:11

user590028

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Or just use forward slashes. – Jayanth Koushik Feb 21 '14 at 11:12
I was adding this exact clarification (just as you posted) – user590028 Feb 21 '14 at 11:13
both approaches didnt help :( – Denys Feb 21 '14 at 11:16

score 0 · Answer 2 · answered Feb 21 '14 at 11:16

0

Or use Python Raw strings:

with open(r'C:\Users\ehwe\Desktop\INPUT_DS_FILE.txt') as old, open(r'C:\Users\ehwe\Desktop\OUTPUT_DS_FILE.txt', 'w') as new:

answered Feb 21 '14 at 11:16

sateesh

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Reading and writing to file

2 Answers2