Aggregate min() function | pandas find min value in row & column
In this pandas tutorial, we will discuss about:
-
aggregate min function in pandas,
-
pandas find min value in row,
-
find min value in pandas column
Aggregate min() function is applied on the pandas DataFrame to find min in pandas dataframe.
DataFrame is an two dimensional data structure that will store data in two dimensional format. One dimension refers to a row and second dimension refers to a column, So It will store the data in rows and columns.
We can create this DataFrame using DataFrame() method. But this is available in pandas module, so we have to import pandas module.
Syntax:
pandas.DataFrame(data)
Where, data is the input dataframe, The data can be a dictionary that stores list of values with specified key.
Example: Create Dataframe
In this example, we will create a dataframe with 4 rows and 3 columns with building data and assign indices through index parameter.
import pandas as pd
#create dataframe from the building data
data= pd.DataFrame({
'length':[5.6,7.8,4.5,5.3],
"breadth":[12.9,4.5,21.5,6.0],
"area":[20,56,43,45]
},index=['one','two','three','four'])
#display the dataframe
print(data)
Output: Dataframe is created below
length breadth area
one 5.6 12.9 20
two 7.8 4.5 56
three 4.5 21.5 43
four 5.3 6.0 45
Lets use above dataframe to understand aggregate min function in pandas.
aggregate min function in pandas
If we want to get the minimum value of the columns in the dataframe or find min in pandas dataframe, then we have to use aggregate functions.
In that, min is one of the function , which will return minimum value (row/column) of the dataframe.
For aggregation, the method used is agg() and for minimum, the method used is min.
There are three scenarios of using this function to find min in pandas dataframe. Let's discuss one by one.
Scenario 1 : min aggregation over the rows pandas
In this scenario to find min in pandas dataframe, we will get the min over each row in the dataframe.
Syntax:
dataframe.agg('min')
where, dataframe is the input dataframe.
Example: pandas find min value in row
import pandas as pd
#create dataframe from the building data
data= pd.DataFrame({
'length':[5.6,7.8,4.5,5.3],
"breadth":[12.9,4.5,21.5,6.0],
"area":[20,56,43,45]
},index=['one','two','three','four'])
#min aggregation over the rows
data.agg('min')
Output: From the above pandas find min value in row example, we will return min aggregation over the rows
length 4.5
breadth 4.5
area 20.0
dtype: float64
Lets see second scenario on find min in pandas dataframe.
Scenario 2 : min aggregation per column
In this scenario to find min in pandas dataframe, we will get the minimum for the mentioned columns in the dataframe.
Syntax:
dataframe.agg({'column' : 'min', ..............})
where, dataframe is the input dataframe and column is the column name to get minimum.
Example: find min value in pandas column
In this find min value in pandas column example, we will get minimum value in length and area columns.
import pandas as pd
#create dataframe from the college data
data= pd.DataFrame({
'length':[5.6,7.8,4.5,5.3],
"breadth":[12.9,4.5,21.5,6.0],
"area":[20,56,43,45]
},index=['one','two','three','four'])
#min aggregation per column
data.agg({'length' : 'min', 'area' : 'min'})
Output: From the above find min value in pandas column example, we will return the min aggregation per column
length 4.5
area 20.0
dtype: float64
Lets see another approach to find min value in pandas column.
Scenario - 3 : min aggregation over the columns
In this find min value in pandas column scenario, we will get the minimum value over each column in the dataframe.
Syntax:
dataframe.agg("min", axis="columns")
where, dataframe is the input dataframe.
Example: find min value in pandas column
import pandas as pd
#create dataframe from the college data
data= pd.DataFrame({
'length':[5.6,7.8,4.5,5.3],
"breadth":[12.9,4.5,21.5,6.0],
"area":[20,56,43,45]
},index=['one','two','three','four'])
# aggregation over the columns
data.agg("min", axis="columns")
Output: From the above example, we will return the aggregation over the columns
one 5.6
two 4.5
three 4.5
four 5.3
dtype: float64
Thus we have seen how to find the minimum value in a column using pandas.
This concludes our session on pandas find min value in row & find min value in pandas column.
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About the Author
Gottumukkala Sravan Kumar 171FA07058
B.Tech (Hon's) - IT from Vignan's University.
Published 1400+ Technical Articles on Python, R, Swift, Java, C#, LISP, PHP - MySQL and Machine Learning
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Published Date :
May 06,2022