CS105 LAB 5: Python

1. Using IDLE
2. Basics: output, variables, operators
3. Python Programs, including the use of for loops

IDLE is a tool for interacting with Python and writing Python programs. You will find IDLE convenient for a number of reasons:

• it gives the appropriate indentation
• it uses colors for reserved words, "strings" etc..
• it makes it easy to create a .py file
• it runs on your own machine
• http://www.python.org/download/
• let's take a tour!

>>>print "best course: cs105 "

>>>#print "best course: cs105"

this was a comment, it is always ignored by the interpreter..

a program will be most commonly ignored by people if it has no comments that explain what it is that it does

>>>print "i can do fast math!"

>>>print 10 **10

>>>c=5

c is a variable.. we assigned it a value

>>>print c

>>>c= c+1

>>>d=c

d is another variable, we assigned it the value of c.. what happens if we change the value of c; does d change?

Who gets the car after 23984 days? (if it is still working..)

Here is a simple program:

print "Hello"
print "How are you?"

1. Write this program in the editor window of IDLE (File->New).
2. Save it as greet.py.
3. Run it by using Run->Run Module or the F5 key.

Here's is a pseudo-code for calculating the Future Value of an investment principal at interest rate apr:

get principal
get apr
get years
for i = 1..years
    principal = principal * (1+apr)
output the future value 

Convert the above pseudo-code to a python program and run using IDLE