When is a directly used file object closed?

[elbin]

In the line:

open("file","a").write("\n")

an object is created, but where does it go afterwards, and is the file "closed" like in:

f = open('file', 'a')
f.close()
 

Is there a problem in not closing files?

[bvdet]

In the line:

open("file","a").write("\n")

an object is created, but where does it go afterwards, and is the file "closed" like in:

f = open('file', 'a')
f.close()
 

Is there a problem in not closing files?

When reading a file, it is not necessary to create a file object as in:

lineList = open('filename').readlines()

When writing or appending to a file, I recommend that you create a file object and explicitly close the object when you are through. That forces the system to flush the output buffers and finish writing the data.

[bartonc]

In the line:

open("file","a").write("\n")

an object is created, but where does it go afterwards, and is the file "closed" like in:

f = open('file', 'a')
f.close()
 

Is there a problem in not closing files?

Although it is not necessary to explicitly close a file, it is good practice to do so.
The file will (if all goes well) be closed when the the object is garbage collected.
If you open a file without keeping a reference to it, there is still an object created which is immediately marked for garbage collection. I cringe when I see people doing this.
If you do keep a reference as in

f = open('filename')

then the file will remain open as long as that reference exists.

Best practice: call close() as soon as you are done with the file.

[ghostdog74]

In the line:

open("file","a").write("\n")

an object is created, but where does it go afterwards, and is the file "closed" like in:

yes, its implicitly closed.