Ctrl + alt + c (Clean Auxiliary files)

Ctrl + alt + 3 (go to start of line) Ctrl + alt + 4 (go to end of line) Ctrl + d (find next element of the same sort) Ctrl +k + Ctrl + d (skip first find next) Ctrl + shift + L (select all elements of the same sort)

Ctrl+l for url Snap windows for explorer alt-tab Windows + ArrowKeys for window moving

The “Shallow Copy” Trap (Mutable Objects) matrix = [[0] * 3] * 3. The Problem: This does not create three independent rows. It creates one row and then places three references to that same row into the outer list. The Symptom: If you change one element (matrix[0][0] = 1), the change appears in every row because they all point to the exact same memory location. The Fix: Use a list comprehension to ensure each row is a unique object: [[0 for _ in range(3)] for _ in range(3)].

Mutable vs. Immutable Objects Integers/Strings: If you multiply [0] * 10, it also repeats references to the same 0. However, because integers are immutable (cannot be changed), you never notice. Changing list[0] = 5 just makes the first index point to a new number rather than modifying the shared 0 object.