How to calculate mean of every column of Dataframe?

Pandas DataFrame.mean()

The mean() function is used to return the mean of the values for the requested axis. If we apply this method on a Series object , then it returns a scalar value , which is the mean value of all the observations in the dataframe.

If we apply this method on a DataFrame object, then it returns a Series object which contains mean of values over the specified axis.

Syntax

DataFrame.mean(axis=None, skipna=None, level=None, numeric_only=None, **kwargs)

Parameters

  • axis: {index (0), columns (1)}.
    This refers to the axis for a function that is to be applied.
  • skipna: It excludes all the null values when computing result.
  • level: It counts along with a particular level and collapsing into a Series if the axis is a MultiIndex (hierarchical),
  • numeric_only: It includes only int, float, boolean columns. If None, it will attempt to use everything, then use only numeric data. Not implemented for Series.

Returns

It returns the mean of the Series or DataFrame if the level is specified.

Example

# importing pandas as pd   
import pandas as pd    
# Creating the dataframe    
info = pd.DataFrame({"A":[8, 2, 7, 12, 6],   
                   "B":[26, 19, 7, 5, 9],    
                   "C":[10, 11, 15, 4, 3],   
                   "D":[16, 24, 14, 22, 1]})     
# Print the dataframe   
info  
# If axis = 0 is not specified, then  
# by default method return the mean over   
# the index axis   
info.mean(axis = 0)  

Output

A     7.0
B    13.2
C     8.6
D    15.4
dtype: float64

Example2

# importing pandas as pd   
import pandas as pd   
# Creating the dataframe    
info = pd.DataFrame({"A":[5, 2, 6, 4, None],   
                   "B":[12, 19, None, 8, 21],   
                   "C":[15, 26, 11, None, 3],  
                   "D":[14, 17, 29, 16, 23]})     
# while finding mean, it skip null values   
info.mean(axis = 1, skipna = True)   

Output

0       11.500000
1       16.000000
2       15.333333
3        9.333333
4       15.666667
dtype: float64