Series.value_counts() - Pandas Series

The Series.value_counts() method is used to count the number of occurrences of each unique value in a Pandas Series. It returns a new Series with the counts of unique values in descending order.

Syntax

The syntax for using the Series.value_counts() method is:

series.value_counts(normalize=False, sort=True, ascending=False, bins=None, dropna=True)

where

• normalize (bool): If True, returns the relative frequency (proportions) of the unique values. Default is False.
• sort (bool): Sorts by value. Default is True.
• ascending (bool): Sort order. Default is False.
• bins (int): Used only with numeric data. Groups the values into half-open bins. Applies only to numerical columns. Default is None.
• dropna (bool): Excludes missing values. Default is True.

Example

Consider the following example:

import pandas as pd

fruits = pd.Series(["apple", "orange", "apple", "banana", "banana", "orange", "apple"])

counts = fruits.value_counts()

print(counts)

Output:

apple     3
orange    2
banana    2
dtype: int64

In this example, a Pandas series named fruits is created with some values. The value_counts() method is called on this series to get the count of unique values. The resulting series, named counts, is then printed to the console.

Explanation

The value_counts() method returns a new Pandas series with the counts of each unique value in the original series. In the example above, the apple value occurs 3 times, orange occurs twice, and banana occurs twice. The resulting new series is sorted in descending order by the number of occurrences of each value.

Use

The value_counts() method is useful for determining the number of occurrences of each unique value in a Pandas series. This can be useful for analyzing data and identifying trends.

Important Points

• The Series.value_counts() method returns a new Pandas series with the counts of each unique value in the original series.
• The new series is sorted in descending order by the number of occurrences of each value.
• The method has several optional parameters that allow for more control over the results.

Summary

The Series.value_counts() method is a powerful tool for analyzing data in a Pandas series. Its ability to count the number of occurrences of each unique value, along with its optional parameters, make it a valuable asset in data analysis and manipulation.