title: How to pass python list dynamically to another python file
body: <p>I am developing an N-Queen Simulation using pygame.</p>
  
  <pre><code>class NQ:
  
      def __init__(self,n):
          self.size = n
          self.columns = [] * self.size
          self.places = 0
          self.backtracks = 0
  
      def place(self, startRow=0): 
          if len(self.columns) == self.size:
  
              return self.columns
  
  
          else:
              for row in range(startRow, self.size): 
                  if self.isSafe(len(self.columns), row) is True: 
                      self.columns.append(row)
                      self.places += 1 
                      return self.place()
  
              else: 
                  lastRow = self.columns.pop()
                  self.backtracks += 1 
                  return self.place(startRow=lastRow + 1)
  
      def isSafe(self, col, row): 
          for threatRow in self.columns: 
              threatCol = self.columns.index(threatRow) 
              if row == threatRow or col == self.columns.index(threatRow):
                  return False 
              elif threatRow + threatCol == row + col or threatRow - threatCol == row - col:
                  return False 
          return True
  
      def process(n):
  
          nqueens = NQ(n)
          nqueens.place(0)
          return nqueens.columns
  </code></pre>
  
  <p>Also I have a pygame procedure in another file to draw chess board which takes a list as input and place them accordingly. 
  If I want to show the movement of queens, how can i pass the list dynamically from the recursive<code>code</code> procedure so that the exact backtracking procedure is visible.
  Thank you </p>