Master FTP Login Methods & Python Memory Management: Interview Answers Explained

Question 1 (Linux)

Describe the two login methods when using FTP for file transfer and explain their differences.

List common FTP file transfer commands.

Answer 1

FTP has two login methods: anonymous login and authenticated login.

Anonymous login uses username anonymous and any valid email address as password; it can only access resources in the FTP directory, typically allowing download only.

Authenticated login uses a real user account and password on the remote system; it provides broader permissions, allowing both upload and download.

FTP also supports two transfer modes: ASCII mode for text files and binary mode for other files.

Common FTP commands include: bin, asc, put, get, mput, mget, prompt, bye.

Question 2 (Python)

How does Python manage memory?

Answer 2

Python’s memory management consists of three mechanisms: reference counting, garbage collection, and memory pooling.

Reference counting : every object has a reference count that increases when a new name is bound to it or when it is placed in a container, and decreases when a name is deleted or goes out of scope. The sys.getrefcount() function returns the current count.

Garbage collection : when an object’s reference count drops to zero it is reclaimed; cyclic references are detected by a periodic collector that breaks cycles to prevent memory leaks.

Memory pooling : Python uses the pymalloc allocator for small objects (≤256 bytes), keeping freed memory in private pools rather than returning it to the OS. Large objects use the system malloc. Separate pools exist for different object types such as integers, floats, and lists.