Python

Python is a scripting language that is unique from other languages in that it uses indentation of the code to form the if-then-else blocks. Other languages will use an explicit start and stop construction, so this shorthand makes the code feel less cluttered. Like Perl, it is supported on all computing platforms (Windows, Unix, Linux, Mac, and mobile devices) and executes immediately without the need for a compile step. The simplicity and self-documenting nature of the Python language make it a favorite language for script writers.

Additional libraries can be called from a Python program which gives it access to many pre-built objects such as network connections, databases and graphics.

Download software: http://www.python.org/

Cost: Free

Instructions to setup software: For Windows, just run the MSI installer available at python.org/download. For Mac OS X, it is already installed on your computer.

Hardware requirements: Any PC or laptop computer

Operating systems supported: Win, Mac OS X, Linux

Difficulty level: 2 out of 5

TRY IT!

1. Install the Python compiler and tools on your computer or laptop. This is available in a single download file from python.org. For Mac OS X and some Linux computers, Python is already installed.

2. Open a text editor (notepad, textedit, or your favorite) and copy/paste the following program into a file. If you installed Python into a Windows computer, it included a program called IDLE, which can edit and run Python programs:

#!/usr/bin/env python3

#...initialize looping variable, assume 'yes' as the first answer
continueYN = "y"

while continueYN == "y":
   #...get temperature input from the user
   sDegreeF = input("Enter next temperature in degrees Fahrenheit (F):";)

   #...convert text entry to number value that can be used in equations
   nDegreeF = int(sDegreeF)

   #...convert temperature from F to Celsius
   nDegreeC = (nDegreeF - 32) * 5 / 9

   print ("Temperature in degrees C is:", nDegreeC)

   #...check for temperature below freezing..
   if nDegreeC < 0:
      print ("Pack long underwear!")

   #...check for it being a hot day...
   if nDegreeF > 100:
      print ("Remember to hydrate!")

   continueYN = input("Input another?")

#exit the program

3. Save it as “temperature.py”

4. Open a command window (cmd.exe, or Unix shell) on your computer and navigate the default directory to the place where you stored “temperature.py”. If you are editing in IDLE, then you can skip this step.

5. Run the program with the command “python temperature.py”. If you are running IDLE, then just select the menu option Run -> Run Module.

TRY THIS

1. Change the messages to have different advice for extreme temperatures.

2. Change the trigger temperatures (hot or cold) to something different.

3. Add another temperature trigger check for very extreme temps.

4. Collect the person’s name before the loop starts (store in a variable) and add this to the output messages.

5. (Advanced) Change the whole program into a currency converter. Input amount in US dollars and convert to Euros.

LEARN MORE

www.python.org/doc — The official documentation site for Python along with links to other tutorial and sample sites.

Learnpython.org -– A step by step tutorial site. Starts with a “Hello World” program and extends into advanced language features.

Google.com -– Search for other code and samples.

RESOURCES, TIPS, TRICKS AND HINTS

Scripting languages do not need a compiler, so you can quickly write and test programs. The Windows installation includes an environment called IDLE, which runs the Python command line in a second window while you make changes in a primary window. For Mac and Linux, this can also be done using Textpad to edit a file in one window and running the command line in a second window.

This allows you to make small changes to the file, save it, and then run it in the other windows. You can grow a simple program into a complex one in this manner.