Variables, Operators, and Function Calls

Today continues on variables and discusses the various operators available to you. We also introduce you to the concept of calling functions in order to run other code.

Read Chapter 2

Read Chapter 2 of your online textbook.

Today in Class

We will discuss and learn about:

• Variable types (string, int, float) and how to determine their types for debugging.
• Standard operators for each type.
• Operator precedence
• Type conversion
• Function calls (print() and input())

You should be able to understand this program.

    print("Enter a time hh,mm,ss")
hours = input()     # Does input() require an argument?
mins = input()
seconds = input()

total = 3600*int(hours) + 60*int(mins) + int(seconds)

print("Elapsed time is", total, "seconds.", end='')  # what does end do?

And this one with different operator + usage:

print("Hello let's talk about types!")
x = 5
y = 6
result = x + y
print(result)
x = '5'
y = '6'
result = x + y
print(result)
print("Why did this happen?")
print("Ok let's try again.")
result = int(x) + int(y)
print(result)
print("What do you think?")

Try running it!

Copy the above into a test.py program in VSCode and give it a run!

Make sure you understand why the output is how it is. Then play around with it. For instance, what happens if you change the + to a multiply * ?