Obtaining the median value over a specified axis of a DataFrame

Overview

The median() function in pandas is used to obtain the median value of the values of a specified axis of the given DataFrame.

Mathematically, median can be defined as the value of a dataset that lies at the midpoint when all the values in the dataset are sorted in ascending or descending order.

Syntax

The median() function takes the syntax shown below:

DataFrame.median(axis=NoDefault.no_default, skipna=True, numeric_only=None, **kwargs)
Syntax for the mean() function in Pandas

Parameter

The median() function takes the following optional parameter values:

  • axis: This represents the name for the row (designated as 0 or `index') or the column (designated as 1 or columns) axis from which to take the median.
  • skipna: This takes a Boolean value. It determines whether null values are to be excluded or not in the calculation of the median.
  • numeric_only: This takes a Boolean value. It determines whether only float, int, or Boolean columns are included in the calculation.
  • **kwargs: This is an additional keyword argument that can be passed to the function.

Example

# A code to illustrate the median() function in Pandas
# importing the pandas library
import pandas as pd
# creating a dataframe
df = pd.DataFrame([[1,2,3,4,5],
[1,7,5,9,0.5],
[3,11,13,14,12]],
columns=list('ABCDE'))
# printing the dataframe
print(df)
# obtaining the median value vertically across rows
print(df.median())
# obtaining the median value horizontally over columns
print(df.median(axis="columns"))

Explanation

  • Line 4: We import the pandas library.
  • Lines 7–10: We create a DataFrame df.
  • Line 12: We print df.
  • Line 15: Using the median() function, we obtain the median values running downwards across the rows (axis 0). We print the result to the console.
  • Line 18: Using the median() function, we obtain the median values running horizontally across columns (axis 1). We print the result to the console.

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