Creating a primary key index by combining relevant columns in Pandas is a way to uniquely identify each row in a DataFrame. This is useful when working with large datasets, as it can improve performance and simplify data manipulation. Here are a few methods to create a primary key index by combining relevant columns in Pandas:
1. Using the "set_index()" method:
One of the simplest ways to create a primary key index is to use the set_index() method. This method sets one or more columns as the index of a DataFrame. You can pass a list of column names to the method to combine them and create a multi-column index.
Example:
2. Using the "MultiIndex.from_arrays()" method:
Another way to create a primary key index is to use the MultiIndex.from_arrays() method. This method creates a multi-level index from arrays of values.
Example:
3. Using the "assign()" method:
You can also create a primary key index by creating a new column with the combined values of relevant columns and then setting that column as the index using the assign() method.