lifo - Python: First In First Out Print -

i'm beginner in python , i'm having issue program:

the program below last in first out (lifo). want make first in first out (fifo) program.

from nodelist import node  class queuell:      def __init__(self):         self.head = none       def enqueueqll(self,item):         temp = node(str(item))         temp.setnext(self.head)          self.head = temp         length = max(len(node.data) node in self.allnodes()) if self.head else 0         print('\u2510{}\u250c'.format(' '*length))         node in self.allnodes():             print('\u2502{:<{}}\u2502'.format(node.data, length))         print('\u2514{}\u2518'.format('\u2500'*length)) 

here nodelist:

class node:      def __init__(self,initdata):         self.data = initdata         self.next = none      def getdata(self):         return self.data      def getnext(self):         return self.next      def setdata(self,newdata):         self.data = newdata      def setnext(self,newnext):         self.next = newnext 

note: "rainbow" should @ bottom of "arc" or in fifo (pic below lifo)

i'm thinking put new def setprevious in nodelist dont know how. (to honest i'm new on these self.head = none stuffs . used write self.items = [])

any , tips appreciated! thank you!

apart learning purposes not advise using custom data structure making lifo or fifo. built in data-type list fine after all.

you can add items using append method , remove them using pop. lifo this:

stack = list() stack.append(1) stack.append(2) stack.append(3)  print stack.pop()  #3 print stack.pop()  #2 print stack.pop()  #1 

if supply integer argument pop can specify element remove. fifo use index 0 first element:

stack = list() stack.append(1) stack.append(2) stack.append(3)  print stack.pop(0)  #1 print stack.pop(0)  #2 print stack.pop(0)  #3