Finding the row number of nth largest value

Python
#1

Finding the row number of the nth largest value in Pandas refers to the process of identifying the row number or index of the nth largest value in a specific column of a pandas dataframe. The row number can be useful when you want to locate or manipulate a particular row in the dataframe.

Here’s a detailed explanation of the methods mentioned to get the row number of the nth largest value in a column in Pandas:

1. Using "nlargest()" and "index()" methods:

The nlargest() method returns the n largest values from a column in descending order. We can then use the index() method to get the index labels of those values. By using [-1] to access the last label in the index, we get the row number of the nth largest value in the column.

Example:
In this example, we are getting the row number of the 3rd largest value in the 'col2' column. First, we use the `nlargest()` method to get the top n largest values in the 'col2' column. Then, we use the `index()` method to get the index labels of those values. Finally, we use [-1] to access the last label in the index, which gives us the row number of the 3rd largest value in the 'col2' column.

2. Using "sort_values()" and "iloc()" methods:

The sort_values() method sorts the dataframe by a specified column in ascending or descending order. We can then use the iloc() method to get the row number of the nth largest value in the column.

Example:
In this example, we are getting the row number of the 3rd largest value in the 'col2' column. First, we use the `sort_values()` method to sort the dataframe by the 'col2' column in descending order. Then, we use the `iloc()` method to access the row at index n-1 (since indexing starts at 0) and use the `name` attribute to get the index label of that row. Finally, we get the row number of the nth largest value in the 'col2' column.

3. Using "argsort()" and "iloc()" methods:

The `argsort()` method returns the indices that would sort an array in ascending order. We can then use the `iloc()` method to get the row number of the nth largest value in the column.

Example: