JohnnyFang

class Node:
    def __init__(self,data):
        self.data = data
        self.next = None 
        

class Solution: 
    def display(self,head):
        current = head
        while current:

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class Command:
  def execute(self):
    pass

  
class Copy(Command):
  def execute(self):
    print("Copying...")

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# Python 3 has a built in feature that allows us to designate a certain method as an abstract method. 
# When a method is decorated as an abstract method it should be overrriden by a subclass.
from abc import ABC, abstractmethod
class AbstractExpression():
  
  @abstractmethod
  def interpret(self):
    pass

class NonterminalExpression(AbstractExpression):

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import pickle
class Originator:
    def __init__(self):
        self.__state = None
        
    def create_memento(self):
        return pickle.dumps(vars(self))
    
    def set_memento(slef, memento):
        selfprevious_state = pickle.loads(memento)

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#  compare each item in a list with the rest, only once?
for index, this in enumerate(mylist):
    for that in mylist[index+1:]:
        compare(this, that)
 

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def arrayChange(inputArray):
    count = 0
    adam = inputArray[0]
    for el in inputArray[1:]:
        if el <= adam:
            count += adam-el+1
            adam +=1
        else:
            adam = el
    return coutn

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# not so Pythonic way
def palindromeRearranging(inputString):
    letter_counts_dict = dict()
    for letter in inputString:
        if letter in letter_counts_dict:
            letter_counts_dict[letter] += 1
        else:
            letter_counts_dict[letter] = 1
    threshold = 0
    for k,v in letter_counts_dict.items():

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class Config(object):
   """
   Common configurations
   """

class DevelopmentConfig(Config):
   """
   Development configurations
   """

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from flask import Flask
app = Flask(__name__)

@app.route("/")
def hello():
    return "Hello World!"

if __name__ == '__main__':
    app.debug = True
    app.run()

JohnnyFang

# instance/config.py
SECRET_KEY = 'b=3=!0^96*8jhkvkfbqf*1!yn-9'
SQLALCHEMY_DATABASE_URI = 'postgresql+psycopg2://USER:PASSWORD@localhost/db_name'