python program, programming guidelines, and IDLE/repl.it

An introduction to the python shell either in IDLE or https://repl.it/

Run IDLE or in the repl.it window
Assigning a value to a variable
Using the python shell as a calculator
Printing a word
Printing a number
Printing the content of a variable
Comparing two numbers
comparing two variables

Writing your first python program:

If you are using IDLE, create “My_Python_Programs” folder in Documents”
If you are using IDLE or repl.it, create a new “Basic_Progrmas” folder in the “My_Python_Programs”
Open a “new window”
Write your first program using the algorithm to find the smallest and largest numbers in a set of 2 integer numbers. Program name: BasicInstructions_YI.py.

NOTE: YI_ represents Your Initials.

Guidelines for writing programs
Every program has to have a header:

Assignment description
Author’s name
Date
Input and output as comments if they are part of the assignment
If the program doesn’t run successfully, write a short paragraph as part of the program header explaining the problem.

Set of instructions:

Comparing two numbers
Deciding which number smaller and which one is larger

Let’s turn the English instructions into computer instructions:

###################################################################
# Mrs. Elia
# python 3.x
# Description: Basic instructions
###################################################################

name = input("Enter your name ")              # prompting the user 
print("Hello", name)                          # displaying a message

x = input("Enter a number ")                  # Assignment operator 
print ("The first number you entered is ",x ) # Why green and black?
y = input("Enter another number ")            # prompting for another number

print ("The two numbers you entered are",x,"and", y)  # printing multiple items

# Anything inside quotes is a "string" or text

###################################################################
#
#  Turn the "string" numbers into "integer" numbers to compare them
#
###################################################################

x = int(x)                                     # convert to string and assign
y = int(y)                                     # convert to string and assign

if x > y:                                   # compare x to y
    print (x, " is bigger than ",y)            # the comparison is true
else:
    print (y, " is bigger than ",x)            # the comparison is false

# end of program

What about if they are both equal to each other?
if x == y:
    print("They are both equal")
else:
if x > y:
        print (x, " is bigger than ",y)
    else:
        print (y, " is bigger than ",x)

Concepts you learned
1. Variables as place holders
2. Keeping an eye on only two variables at a time

More concepts to learn
3. Pseudocode
4. Flowchart

More on “ordering”

Install python and IDLE in your home computer videos or work on repl.it:
Write English instructions (pseudocode) to order 3 numbers from small to large.
Use the following data to “trace” your algorithm.
89 101 2
Explain your strategy in a short paragraph.

Videos From the “Resources Tab” above:
Python programming using repl.it

Python Programming using IDLE

Creating a file in repl.it

Creating python file in IDLE