Python Coding challenge - Day 660| What is the output of the following Python Code?

 

Code Explanation:

1. Importing the pandas library

import pandas as pd

Imports the pandas library with the alias pd, which is used for data manipulation and analysis.

2. Creating a DataFrame df

df = pd.DataFrame({'A': [1, 2, 3, 4], 

                   'B': [5, 6, 7, 8]})

Creates a pandas DataFrame named df with two columns:

'A' contains [1, 2, 3, 4]

'B' contains [5, 6, 7, 8]

3. Creating a filtered slice of df

df_slice = df[df['A'] > 2]

Creates a new DataFrame df_slice by selecting rows where the value in column 'A' is greater than 2.

df_slice will have rows where 'A' is 3 and 4, so:

   A  B

2  3  7

3  4  8

4. Modifying column 'B' in df_slice

df_slice['B'] = 0

Attempts to set the values in column 'B' of df_slice to 0 for all rows in the slice.

Important: This creates a SettingWithCopyWarning because df_slice is a filtered view or copy of df.

Modifying df_slice does not modify the original df unless explicitly done using .loc.

5. Printing the sum of column 'B' in the original DataFrame df

print(df['B'].sum())

Calculates the sum of column 'B' in the original DataFrame df.

Since df was not modified by changing df_slice, column 'B' remains [5, 6, 7, 8].

Sum = 5 + 6 + 7 + 8 = 26

Final output:

26

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