Summary  
This chapter covers techniques for counting unique values in a column by leveraging data structures (like sets or dictionaries) and built-in functions to aggregate distinct elements.  

General domain of usage  
Data analysis

A comprehensive course focused on mastering column-based operations in Python, covering a wide range of techniques for manipulating, analyzing, and transforming data columns. The course features 20 chapters, each exploring a unique aspect of column operations, with three types of question-based chapters: single question, multiple questions, and mixed single/multiple questions.

Explore the foundational concepts and basic operations for working with columns in Python.

Delve into techniques for transforming and manipulating column data.

Learn to aggregate and analyze data at the column level.

Explore advanced methods for manipulating and analyzing columns.

Counting Unique Values in Columns

Counting Unique Values in Columns