Ranking Rows of Pandas DataFrame

# import the required packages 
import pandas as pd 

# Define the dictionary for converting to dataframe 
movies = {'Name': ['The Godfather', 'Bird Box', 'Fight Club'],
         'Year': ['1972', '2018', '1999'],
         'Rating': ['9.2', '6.8', '8.8']}

df = pd.DataFrame(movies)
print(df)

# Create a column Rating_Rank which contains
# the rank of each movie based on rating
df['Rating_Rank'] = df['Rating'].rank(ascending = 1)

# Set the index to newly created column, Rating_Rank
df = df.set_index('Rating_Rank')
print(df)

# Sort the dataFrame based on the index
df = df.sort_index()
print(df)

# Create a dictionary with student details
student_details = {'Name':['Raj', 'Raj', 'Raj', 'Aravind', 'Aravind', 'Aravind',
                             'John', 'John', 'John', 'Arjun', 'Arjun', 'Arjun'],
                   'Subject':['Maths', 'Physics', 'Chemistry', 'Maths', 'Physics',
                             'Chemistry', 'Maths', 'Physics', 'Chemistry', 'Maths',
                                                           'Physics', 'Chemistry'],
                   'Marks':[80, 90, 75, 60, 40, 60, 80, 55, 100, 90, 75, 70]
               }

# Convert dictionary to a DataFrame
df = pd.DataFrame(student_details)
print(df)

# Create a new column with Marks 
# ranked in descending order
df['Mark_Rank'] = df['Marks'].rank(ascending = 0)

# Set index to newly created column 
df = df.set_index('Mark_Rank')
print(df)

# Sort the DataFrame based on the index 
df = df.sort_index()

print(df)