sumOfInt

Example Python program sumOfInt.py

Methods

• def sumOfInt(lb,ub):
• def sumOfSquareOfInt(lb,ub):
• def sumOfCubeOfInt(lb,ub):
• def sumOfInts(f, lb, ub):
• def sumOfInts(f, lb, ub):

Code

Python example

lb=0
ub=100
def sumOfInt(lb,ub):
  total = 0
  for i in range(lb,ub + 1):
    total = total + i
  return total  

  # Traditional way to do square of sum of Integers
  def sumOfSquareOfInt(lb,ub):
    total = 0
    for i in range(lb,ub):
      total = total + (i * i)
    return total

  # Traditional way to do cube of sum of Integers
  def sumOfCubeOfInt(lb,ub):
    total = 0
    for i in range(lb,ub):
      total = total + (i * i * i)
    return total

    # Anonymous frunction or lamda function. Every thing remains same as in the firat function sumOfInt()
    def sumOfInts(f, lb, ub):
      total = 0
      for i in range(lb, ub + 1):
        total = total + f(i)     # The f(i) part is unknown and a function is passed as f and invokes f(i) with one argument
      return total

    sumOfInts(lambda i: i, 1,100)     # Anonymous function (functionality with no name) is passed using lambda keyword 
    sumOfInts(lambda i: i*i*i, 1,100) # cube of Ints
    sumOfInts(lambda i: i*i, 1,100)   # square of Ints
    sumOfInts(lambda i: i*2, 1,100)   # integer multiply by 2

    # sumOfInt with two Arguments
    def sumOfInts(f, lb, ub):
      total = 0
      c = 2
      for i in range(lb, ub + 1):
        total = total + f(i, c)
      return  total

    sumOfInts(lambda i,c: i+c, 1, 100)  # i+c is the functionality for f(i, c) the 2 arguments passed

    # sumOfInt only if they are even else just leave them
    sumOfInts(lambda i: i if(i%2 == 0) else 0 ,1 , 100)

    #List is a collection in python
    #Range is a special kind of list in python. To conver range to list to following
    l = list(range(1,101))

    # To access the list element
    l[0]
    l[1]
    l[:5]
    l[-5]
    l.count(1) # to find how many times 1 been repeated in the list l
    l.sort()
    l.pop(0) # to delete
    l.indexOf(6)  # to find where 6 is
    l.indexOf(2,6) # find on which index 6 is starting from index 2
    l.append(101)
    l.reverse()

    help(l)



    # Set --> cant have duplicates - rest all similiar to list
    set(l)  # duplicates will be eliminated

    # To open a file in python
    orderItems = open("c:\\retail_db\\order_items\\part-00000")
    type(orderItems) # file 
    orderItems = open("c:\\retail_db\\order_items\\part-00000").read()
    type(orderItems)  #str
    orderItems = open("c:\\retail_db\\order_items\\part-00000").readlines() #retrun collection of str with \n with each element

    # to avoid it use read().splitlines()
    orderItems = open("c:\\retail_db\\order_items\\part-00000").read().splitlines() # no \n in the array of elements
    orderItems[:5]
    len(orderItems)

    # Find a file in linux
    find . -name "*.tsv" -type f/d   # file for file / d  for directory
    find . -name "*.tsv" -type f | wc -l

    #Dict -- {Key Value} Pair collection
    d = {1 : "Scott", 2 : "Jay"}
    d[3]="Tiger"    # to append new key value pair
    d[2]="Woods"    # will replace "Jay" with "Woods"
    d.get(1)        # Scott
    d.has_key(1)    # returns true or false
    d.items()       # create collection out of it
    d.iterkeys()    # to get only the keys
    d.itervalues()  # to get only the values

Useful Links

• Articles: https://python-commandments.org/
• Python shell: https://bsdnerds.org/learn-python/
• Tutorial: https://pythonprogramminglanguage.com/