sorting data (latest on top) with particular date in CSV file

Question

I have a excel file which i read and convert into csv file after get two column out of all column in file . I want a csv file which have two columns which is Oder date(Latest on top) and Sales. what i have to do?

I want a csv file which have two column 1st is Order date (latest date on top) and second is Sales with particular date. So how to sort date in descending order(latest to old) with particular sales.

my Python Script is here

import csv
from os import pardir, sep
import pandas as pd
import openpyxl

# Read Excel File
read_file = pd.read_excel("Orders-With Nulls.xlsx")
# Create CSV file with all data
read_file.to_csv("demo.csv" , index=None , header=True)

# Read Specific column
col_list = ['Order Date' , 'Sales']
df = pd.read_csv("demo.csv" , usecols=col_list)

# Print Two Columns in command
df.sort_values(by="Order Date")
print(df)
df['Order Date'] = pd.to_datetime(df['Order Date'])
max_date = df['Order Date'].max()
print(max_date)

# Create new CSV file with only two column 
try:
    with open("new.csv" , "r") as new_csv:
        if new_csv:
            readcsv = pd.read_csv("new.csv" , usecols=col_list)
            print(readcsv) 
except:
    df.to_csv("new.csv" , sep=',' , )
    df.sort_values(by="Order Date")