Classe PgConnector

# file name: pgConnector.py

import psycopg2

class PgConnector:
  def __init__(self, usr, pwd, db_name, print_flag):
    try:
      # connection to the database
      self.connection = psycopg2.connect(
        user = usr,
        password = pwd,
        host = "127.0.0.1",
        port = "5432",
        database = db_name
      )
      # used to perform database operations
      self.cursor = self.connection.cursor()
      self.print_flag = print_flag
    except (Exception, psycopg2.Error) as error :
      print ("Error while connecting to PostgreSQL", error)

  def __display_query(self, query):
    str_max_size = 80

    if(self.print_flag == 'n'):
      return
    elif(self.print_flag == 'f' or len(query) <= str_max_size):
      print("QUERY: " + query)
    elif(self.print_flag == 's'):
      print("QUERY: " + query[:str_max_size] + "...")

  def fetchless_query(self, query):
    try:
      self.__display_query(query)

      self.cursor.execute(query)
    except (Exception, psycopg2.Error) as error :
      print (error)

  def do_query(self, query):
    try:
      self.__display_query(query)

      self.cursor.execute(query)
      return self.cursor.fetchall()
    except (Exception, psycopg2.Error) as error :
      print (error)

  def close(self):
    if(self.connection):
      self.cursor.close()
      self.connection.close()
      print("PostgreSQL connection is closed")