Stack<char> stack = new Stack<char>();
    Queue<char> queue = new Queue<char>();
    
    void pushCharacter(char ch) 
    {
        stack.Push(ch);    
    }
    
    void enqueueCharacter(char ch)
    {
        queue.Enqueue(ch);
    }
    
    public char popCharacter()
    {
       return stack.Pop();
    }
    
    public char dequeueCharacter()
    {
        return queue.Dequeue();
    }

import queue

class Solution:
    def __init__(self):
        self.queue = queue.Queue()
        self.stack = queue.LifoQueue()
    
    def pushCharacter(self,ch):
        self.stack.put(ch)
        
    def enqueueCharacter(self,ch):
        self.queue.put(ch)
    
    def popCharacter(self):
        return self.stack.get()
    
    def dequeueCharacter(self):
        return self.queue.get()

Python 3 

class Solution:
    # Write your code here
    def __init__(self):
        self.stack = []
        self.queue = []
        
    def pushCharacter(self, data):
        self.stack.append(data)
        
    def popCharacter(self):
        return self.stack.pop()
        
    def enqueueCharacter(self, data):
        self.queue.append(data)
    
    def dequeueCharacter(self):
        return self.queue.pop(0)

class Solution {
  //Write your code here
  private var stack: [Character] = []
  private var queue: [Character] = []
  
  func pushCharacter(ch: Character) {
      stack.append(ch)
  }
  
  func popCharacter() -> Character {
      stack.removeLast()
  }
  
  func enqueueCharacter(ch: Character) {
      queue.append(ch)
  }
  func dequeueCharacter() -> Character {
      queue.removeFirst()
  }
}

LinkedList stack = new LinkedList();
    LinkedList queue = new LinkedList();
    
    void pushCharacter(char ch){ stack.addFirst(ch); }
    
    char popCharacter(){ return (char) stack.remove(0); }
    
    void enqueueCharacter(char ch){ queue.addLast(ch); }
    
    char dequeueCharacter(){return (char) queue.remove(0); }