filename = "data.txt"
with open(filename, "r") as file:
    file_contents = file.readlines()
    file_contents = [line.strip() for line in file_contents]

print("File contents:")
for line in file_contents:
    print(line)

print(123)

import subprocess

class CommandRunner:
    def run_command(self, command):
        command_process = subprocess.Popen(command, shell=True, stdout=subprocess.PIPE, text=True)
        output = command_process.communicate()[0].strip()
        return_code = command_process.returncode
        return output, return_code

def main():
    # Create instance of CommandRunner
    runner = CommandRunner()
    
    # Define the command
    command = 'ping -c 4 localhost'
    
    try:
        # Run the command and get output and return code
        output, return_code = runner.run_command(command)
        
        # Print the output and return code
        print(f"Command output:\n{output}")
        print(f"Return code: {return_code}")
        
    except Exception as e:
        print(f"An error occurred: {e}")

if __name__ == "__main__":
    main()

print('hello, world')

x[cat_var].isnull().sum().sort_values(ascending=False)

# Input for row and column
R = int(input())
C = int(input())

# Using list comprehension for input
matrix = [[int(input()) for x in range (C)] for y in range(R)]