File I/O: Reading and Writing Files in Python
Covers how Python programs persist data by reading from and writing to files. Explains the open() function and its modes (read, write, append, binary), demonstrates reading a file all at once, line by line, and into a list with readlines(), and shows overwrite versus append behavior. Introduces the with statement as the idiomatic way to ensure files close automatically, explains try-except handling for missing files, and walks through binary file operations. Practical exercise builds a timestamped log system with a view command.