Is explicitly closing files important?

Question

In Python, if you either open a file without calling close(), or close the file but not using try-finally or the \"with\"

Answer 1

Although it is quite safe to use such construct in this particular case, there are some caveats for generalising such practice:

• run can potentially run out of file descriptors, although unlikely, imagine hunting a bug like that
• you may not be able to delete said file on some systems, e.g. win32
• if you run anything other than CPython, you don't know when file is closed for you
• if you open the file in write or read-write mode, you don't know when data is flushed