# Python Coding Best Practises

• 👉Best Practise 1 → Using enumerate() - Fetch elements from list
  

  # List Variable
  example = ['use','enumerate','instead','of','iteration']
  
  # Ideal Way
  for i in range(len(example)):
      print(f"# {i + 1}: {example[i]}")
  
  # Enemurate
  for i, value in enumerate(example, 1):
      print(f"# {i}: {value}")
  

• 👉Best Practise 2 → Using zip() - Fetch elements from multiple lists
  

  # Lists 
  Employees = ['Employee1','Employee2','Employee3','Employee4']
  Age = [30,25,35,40]
  
  # Ideal Way
  for i in range(len(Employees)):
      employee = Employees[i]
      age = Age[i]
      print(f"Employee name is {employee} and age is {age}")
  
  # Pythonic way - zip
  for employee, age in zip(Employees, Age):
      print(f"Employee name is {employee} and age is {age}")
  

• 👉Best Practise 3 → Using reversed() - Fetch elements reversly
  

  # Lists 
  Employees = ['Employee1','Employee2','Employee3','Employee4']
  
  # Ideal way
  for i in range(1,len(Employees) + 1):
      print(f"Approach 1 - Employee came to office after covid 19 is {Employees[-i]}")
  for employee in Employees[::-1]:
      print(f"Approach 2 - Employee came to office after covid 19 is {employee}")
  
  # Pythonic way - reversed()
  for employee in reversed(Employees):
      print(f"Using revered -  Employee came to office after covid 19 is {employee}")
  

• 👉Best Practise 4 → Using filter() - Data Filtering
  

  # List
  numbers = [1,2,3,4,5,6,7,8,9,10]
  
  #Ideal way
  for number in numbers:
      if number % 2:
          print(f"Odd Number : {number}")
  
  # Pythonic way - filter()
  for number in filter(lambda x: x %2, numbers):
      print(f"Odd Number : {number}")
  

• 👉Best Practise 5 → Using Chain() - Concatenate values from lists
  

  from itertools import chain
  
  #Lists
  oddValues = [1,3,5,7,9]
  evenValues = [2,4,6,8,10]
  
  # Ideal way
  values = oddValues + evenValues
  for value in values:
      print(f"value is : {value}")
  
  # Pythonic way - chain()
  for value in chain(oddValues, evenValues):
      print(f"value is : {value}")
  

• 👉Best Practise 6 → Using Dictionaries() - Retrieve keys & values from dictionary
  

  # Dict
  Employees = {"Employee1": 30, "Employee2": 35, "Employee3": 40, "Employee4": 45}
  
  #Ideal way
  for key in Employees:
      print(f"Employee Name is : {key}")
  for key in Employees.keys():
      print(f"Employee Name is : {key}")
  for value in Employees.values():
      print(f"Age is : {value}")
  for value in Employees:
      print(f"Age is : {Employees[value]}")
  
  #Pythonic way
  for key, value in Employees.items():
      print(f"Employee came to office after covid 19 is {key} and age is {value}")
  

• 👉Best Practise 7 → Using Comprehension() - Comprehensions for lists, dictionaries & set
  

  ### list
  numbers = [1,2,3,4,5,6,7,8,9,10]
  
  #Ideal way
  squaredNumbers = list()
  for square in numbers:
      squaredNumbers.append(square * square)
  print(squaredNumbers)
  
  #Using list comprehension
  squaredNumbers = [x * x for x in numbers]
  print(squaredNumbers)
  
  #Ideal way
  squaredNumbers = dict()
  for square in numbers:
      squaredNumbers[square] = square * square
  
  #Using list comprehension
  squaredNumbers = {x: x*x for x in numbers}
  print(squaredNumbers)
  
  #Ideal way
  squaredNumbers = set()
  for square in numbers:
      squaredNumbers.add(square)
  print(squaredNumbers)
  
  #Using list comprehension
  squaredNumbers = [x*x for x in numbers]
  print(squaredNumbers)
  

• 👉Best Practise 8 → Using else clause - For and While Loops
  

  # For Loop
  for n in range(2, 10):
      for x in range(2, n):
          if n % x == 0:
              print( n, 'equals', x, '*', n/x)
              break
      else:
          # loop fell through without finding a factor
          print(n, 'is a prime number')
  
  # While Loop
  count = 2
  while (count < 1):     
      count = count+1
      print(count) 
      break
  else: 
      print("No Break")
  

• 👉Best Practise 9 → Accept Multiple Inputs, remove duplicates, call by reference..etc
  

  # Tip1: Accept Multiple Inputs
  
  # Traditional Approach
  
  x = input("Enter Any Number: ")
  print(x)
  
  y = input("Enter Any Number: ") 
  print(y)
  
  z = input("Enter Any Number: ") 
  print(z)
  
  t = input("Enter Any Number: ") 
  print(t)
  
  p = input("Enter Any Number: ") 
  print(p)
  
  # Pythonic way
  x,y,z,t,p = input("Enter Any Number: ").split(' ')
  print(x,y,z,t,p)
  
  # Tip2: Multi Condition Check
  
  salary = 40000
  age = 25
  weight = 70
  
  # Traditional Approach
  
  if salary > 20000 and age > 20 and weight > 65:         
      print ("All conditions satisfied")
  
  if salary > 20000 or age > 20 or weight > 65:
      print ("Any one condition is satisfied")
  
  # Pythonic way using list
  
  check = [
      salary > 20000,
      age > 20,
      weight > 65
  ]
  
  if all(check):
      print("Pythonic way of checking conditions")
  
  if any(check):
      print("Pythonic way of checking any one condition")
  
  # Tip 3: swapping in python
  
  # Traditional approach
  
  x = "tip1"
  y = 'tip2'
  
  temp = x
  x = y
  y = temp
  
  print(x,y)
  
  # Pythonic way
  x = 'tip3'
  y = 'tip4'
  x,y = y,x
  print(x,y)
  
  # Tip 4: Removing duplicates
  
  # Traditional approach - with out list comprehension
  numbers = [1,2,1,3,4,2,1,2,5,67,2,3,56,78,34,12,3,4,5,6,7,8]
  result = []
  for num in numbers:
      if num not in result:
          result.append(num)
  print("final list is :" + str(result))
  
  # with list comprehension
  resultComp = []
  [resultComp.append(num) for num in numbers if num not in resultComp]
  print("final list using comprehension:" + str(resultComp))
  
  # Pythonic way
  
  # Using set
  resultSet = list(set(numbers))
  repeatedNumbers = max(set(numbers), key=numbers.count)
  print("Using set final list is :" + str(resultSet))
  print("Most repeated is :", repeatedNumbers)
  
  # Using Dictionary
  resultDict = list(dict.fromkeys(numbers))
  repeatedNumbers = max(dict.fromkeys(numbers), key=numbers.count)
  print("Most repeated is :", repeatedNumbers)
  print("Using dictionary final list is :" + str(resultDict))
  
  # Tip 5: Call by Reference
  
  # Traditional way of implementing the sum function
  def finalString(x,y):
      return x + y
  print(finalString('Python is very simple',' to learn'))
  
  # Using Pythonic way
  
  def finalString1(*x):
      result = ''
      for s in x:
          result += s
      return result
  
  print(finalString1('Python is very simple', ' to learn', ' and can be used \
  in', ' Test Automation, Machine learning, Data Science, Web', \
  'desktop apps development.'))
  
  # Tip 6: Reverse String
  
  # Traditional approach
  s = 'python is fun to learn'
  print(s[::-1])
  
  # Pythonic way
  s = 'python is fun to learn'[::-1]
  print(s)
  
  # Tip 7: Palidrome
  
  checkString = input("Enter the string value :")
  result = checkString.find(checkString[::-1])==0
  if result:
      print("String is Palindrome " + str(result))
  else:
      print("Not Palindrome")