3 pages

Part 1:

Python comes with a program called an IDLE, which belongs to a type of software known in computer science as an IDE (Integrated Development Environment). IDE’s make programming easier, because they color the code for you, give you quick access to built in functions, debug your code, and allow you to run your code from the IDE instead of using the command line.

We will use IDLE in this course, but you are welcome to use ANY IDE you like! Or if you simply like to go old school and type your programs in a text editor (like Notepad) and run it manually through the command prompt, that is fine also! 🙂

Follow these steps to write your 1st Python program with IDLE:

1- Start IDLE, and select New File from the File menu

2- Type: print (“Hello world”) 

3- Save the file, by going to the File menu, make sure to save the file as with a .py extension. So you can call it hello.py or bifs617_wk2.py

4- Run the program by going to the Run menu and select Run Module

5- Congratulations! You’ve written and run your 1st Python program 😉

Questions:

1- What is print in your program actually doing? And why is “Hello world” between double quotes?

2- Add your name and the date to the code above, as comment lines (see Chapter 2 of text book on how to do this)

3- Take a snap shot of your code and paste it (or attach it) to your response. Also mention any issues you might have had.

Part 2: One of the key elements of designing a good program is to allow the user(s) to interact with it. You can do so by asking the user to input a file name, a string representing a DNA sequence, or just a number. These input that are coming in from the user get stored in variables, and make your program more interactive. They also allow you to write a general program that can work for any input (the user (or you) can run your program 100 times and each time input a different DNA sequence for instance).

The Python function to ask for use input, is simply called input()

Here is an example of how it can be used:

DNA = input(“Enter a DNA sequence”)

When you run this, you will see the string “Enter a DNA sequence”, followed by a blinking line. That means Python is waiting for you to type in something! Once you type in a bunch of characters and hit enter, Python will grab what you typed and assign it to the variable DNA. So the string the user typed is now stored in memory and can be accessed by using the name DNA.

Here is an exercise:

Ask a user for 5 number. Use the input function, and store each number in a variable. Then calculate the sum and average of the numbers. Print out both the sum and average to the screen.

Post your code and the results of your calculation here (snap shot would be fine). In the conferences you are encouraged to help one another to solve the exercises (not so for the assignments which are individual tasks!).