Pandas count unique values in multiple columns. unique () You can use pd.

Pandas count unique values in multiple columns. Jan 19, 2024 · pandas. For example, this can be used in testing your code. This method is useful when you want distinct values and their count. unique() only works for a single column, so I suppose I could concat the columns, or put them in a list/tuple and compare that way, but this seems like something pandas should do in a more native way. This will do a group by which will by default pick the unique combinations and calculate the count of items per group The reset_index will change from multi-index to flat 2 dimensional. See full list on statology. Jul 23, 2025 · Pandas series aka columns has a unique () method that filters out only unique values from a column. DataFrame. unique ()to get all unique values in a column. Mar 4, 2024 · Problem Formulation: When working with data frames in Python’s Pandas library, it’s common to encounter the need to extract unique values across multiple columns. Given a Pandas DataFrame that has multiple columns with categorical values (0 or 1), is it possible to conveniently get the value_counts for every column at the same time? For example, suppose I Feb 8, 2016 · unique combinations of values in selected columns in pandas data frame and count Asked 9 years, 6 months ago Modified 3 years, 7 months ago Viewed 318k times Jul 15, 2025 · Let's discuss how to count distinct values of a Pandas DataFrame column. Using pandas. unique () You can use pd. The first output shows only unique FirstNames. Oct 31, 2019 · Pandas count distinct multiple columns in a dataframe and group by multiple columns [duplicate] Asked 5 years, 9 months ago Modified 3 years, 1 month ago Viewed 21k times. org Jul 6, 2022 · Count Unique Values in Pandas July 6, 2022 In this tutorial, you’ll learn how to use Pandas to count unique values. size (). value_counts() returns unique values and their counts as a Series pandas. May 29, 2015 · SELECT DISTINCT col1, col2 FROM dataframe_table The pandas sql comparison doesn't have anything about distinct. Series. Learn how to get unique values as a list, get unique values across columns and more! Nov 12, 2024 · How to count the unique values of a column in Pandas DataFrame? – When working on machine learning or data analysis with Pandas we are often required to get the count of unique or distinct values from a single column or multiple columns. To get only the columns you need into a dataframe you could do df. And the end is to remove the count of items column. nunique() return the number of unique values as either an int or a Series This article begins by explaining the basic usage of each method, then shows how to get unique values and their counts, and more. Apr 1, 2023 · Pandas provides a lot of different ways to interact with unique values. You’ll learn how to count unique values in a column, in multiple columns, and in an entire DataFrame. To count them, apply len ()to the result. Being able to count unique values can have important use cases. . drop (columns=0). Feb 18, 2022 · Count distinct values in a column with values_counts We can easily able to use the Series method value_counts to find the number of unique occurrences in a Pandas DataFrame column. groupby ( ['C1', 'C2', 'C3']). nunique() and pandas. For instance, if you have a dataframe with two columns representing ‘Product’ and ‘Manufacturer’, you may want to retrieve a list of all unique combinations. We can extend this method using pandas concat () method and concat all the desired columns into 1 single column and then find the unique of the resultant column. reset_index (). wcvir mph vvwmh tyzaae evql uphdouh ugsbzbi bqgqqa zohkum vug