Advanced Python Programming

Chapter 11

What is a file descriptor, and in what ways can it be handled in Python?

A file descriptor is used as a handle on an opened external file in a program. In Python, a file descriptor is handled by either using open() and close() functions or using the with statement; for example:

• f = open(filename, 'r'); ... ; f.close()
• with open(filename, 'r') as f: ...

What problem arises when file descriptors are not handled carefully?

Systems can only handle a certain number of opened external files in one running process. When that limit is passed, the handles on the opened files will be compromised and file descriptor leakage will occur.

What is a lock, and in what ways can it be handled in Python?

A lock is a mechanism in concurrent and ...