在python中关闭时写作

Question

i want to write to text file without closing because i don't know what i'll stop close,i'll explain the hole issue

i've create text called resume.txt , so after each specific processes in my project it will overwrite in resume.txt so every time my project start it will check that file to know the last processes so my issue after each writing i have to close to apply it and i don't really think this is good i think there is better solution

this code will not work

wr = open('resume.txt','w')
login(usr,pas)
wr.write('login')
post(msg,con)
wr.write('post')
..so on 

the issue is how to write without closing , i can't write the wr.close at the end because it might be terminated by the user or connection time out .. etc

Answer 1

Not sure if this applies to your code, but what about wrapping in a with block?

with open('resume.txt','w') as wr:
    login(usr,pas)
    wr.write('login')
    # This is hacky, but it will go to the beginning 
    # of the file and then erase (truncate) it
    wr.seek(0)
    # I think you wanted to do this after you tried an action, 
    # but you can move it to wherever you want
    post(msg,con)
    wr.truncate()
    wr.write('post')

This will ensure that the file is closed on error. When you want to close the file, just start your next code on the same level as with with :

with open('resume.txt','w') as wr:
    login(usr,pas)
    wr.write('login')
    wr.seek(0)
    post(msg,con)
    wr.truncate()
    wr.write('post')
    # wr.seek(0) ...

# Next steps...

I would also recommend checking out the logging module to see if that can accomplish what you want.

Answer 2

first of all i'd like to thank tMC

the solution is

wr = open('resume.txt','w')
login(usr,pas)
wr.write('login')
wr.flush()
post(msg,con)
wr.seek(0)
wr.write('post')
wr.flush()

i've used flush() to write and apply and seek(0) for overwriting

Answer 3

Try the with statement . A little comlicated to understand, but should do exactly this.