Calculating Minimum Values

The min() method on a DataFrame returns the smallest value from each column (or each row, if you specify the axis). It works across all data types — for numbers it gives the numerical minimum, and for strings it gives the alphabetically smallest value.

When you call df.min() without any arguments, it computes the minimum of every column in the DataFrame. For example, if you have a DataFrame df containing student marks, print(df.min()) will show the lowest mark in each subject column, and also the alphabetically first name in the Name column.

Finding Minimum Marks for a Specific Student

The textbook demonstrates this with a practical example: finding the minimum marks obtained by the student 'Mishti' across all unit tests for each subject.

First, you filter the DataFrame to get only the rows where the Name column equals 'Mishti':

dfMishti = df.loc[df.Name == 'Mishti']

This creates a new DataFrame dfMishti containing only Mishti's records. Printing it shows all her unit test scores:

dfMishti[['Maths','Science','S.St','Hindi','Eng']].min()

The output is:

Maths      15
Science    18
S.St       20
Hindi      22
Eng        20
dtype: int64
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