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

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()

my_list = [1, 2, 3, 4, 5]
removed_element = my_list.pop(2)  # Remove and return element at index 2
print(removed_element)  # 3
print(my_list)  # [1, 2, 4, 5]

last_element = my_list.pop()  # Remove and return the last element
print(last_element)  # 5
print(my_list)  # [1, 2, 4]

print(“Hello World”)

primes=[]
products=[]

def prime(num):
    if num > 1:
        for i in range(2,num):
            if (num % i) == 0:
                return False
        else:
            primes.append(num)
            return True

for n in range(30,1000):
    if len(primes) >= 20:
        break;
    else:
        prime(n)

for previous, current in zip(primes[::2], primes[1::2]):
    products.append(previous * current)
    
print (products)

#question1.py
def rose(n) :
  if n==0 : 
    yield []
  else :
    for k in range(0,n) :    
      for l in rose(k) :
        for r in rose(n-1-k) :      
            yield [l]+[r]+[r]
            
def start(n) :
  for x in rose(n) : 
      print(x) #basically I am printing x for each rose(n) file


print("starting program: \n")
start(2) # here is where I call the start function