Can't read a file with w+

Question

heres the code

doc = open(path, 'w+')
lines = []
i = 0
for line in doc:
    lines.append(line)
    i += 1
    if i == 1:
        money = int(line)
print(lines)

heres what is returns

[]

the text file contains one line that says "1000"

I tried to resolve the issue by opening it with r, close it, and open it again with w. But for some reason it just deletes all of the text in the file when I try to write anything.

if you want to append, use `a`. `w` will overwrite the content — drum, Sep 11 '21 at 23:25
Can you read the file with append? I just assumed you wouldn't be able to. — legituser42, Sep 11 '21 at 23:26

score 2 · Accepted Answer · answered Sep 11 '21 at 23:26

2

opening it with w+ will overwrite the existing file with a new empty file (which you can then both write and read from) ...

you probably want to open it with a+ (to append) this will put the pointer at the end of the file and then to read before that you will need to use open_file.seek(0) (to go to the beginning of the file)

answered Sep 11 '21 at 23:26

Joran Beasley

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Thanks for the help. I didn't realize there was a cursor. I'm new to python. – legituser42 Sep 11 '21 at 23:28
Of course there is a cursor - how else can `for line in doc:` give you a different line each time? – Karl Knechtel Sep 11 '21 at 23:32
I remember thinking that it just read the file like a list – legituser42 Feb 28 '23 at 15:52

Can't read a file with w+

1 Answers1