Write function not working, read function does

Question

When I use a write function in this code nothing happens, read works fine. Any reason why?

if userinp == ('save'):
    save = open("save.txt",'r')
    print(save.read())
    save = open("save.txt",'a')
    save.write("pop")

save.txt: test

output: test

desired output: pop

thank you for the downvotes :)

Possible duplicate of [open file for both reading and writing?](https://stackoverflow.com/questions/6648493/open-file-for-both-reading-and-writing) — Sayse, Sep 13 '18 at 09:06
The file is likely buffered. `save.flush()` will make sure the contents is written to disk. `save.close()` will also flush the buffer. — Peter Wood, Sep 13 '18 at 09:13

score 0 · Answer 1 · answered Sep 13 '18 at 09:06

To replace the word 'test' in b.txt with 'pop', do the following:

if userinp == ('save'):
    save = open("b.txt",'r')
    print(save.read())
    save = open("b.txt",'w')
    save.write("pop")
    save.close()

The option of 'a' in save = open() appends the word 'pop' to the file, the 'w' option overwrites the content.

score 0 · Answer 2 · answered Sep 13 '18 at 09:06

0

Perhaps the content is in the buffer and not written to file yet.

You can add save.close() after writing so that the buffer is flushed out to the file.

Alternatively, you can do save.flush() to perform a manual flush without closing the file.

answered Sep 13 '18 at 09:06

sid-m

score 0 · Accepted Answer · answered Sep 13 '18 at 09:10

0

FYI: with is taking care of 'close` calls so that we don't have to:

with open('foo.txt', 'w') as f:
    f.write('bar')

answered Sep 13 '18 at 09:10

meissner_

3 Answers3