I opened the page on my computer and dragged over the text, then selected Copy, I then pasted it into a text document.
I could have saved the document on my desktop, and had it available anytime.
This is the first section, you could do this with the whole thing if you need to, one chapter at a time.
I'm assuming that the site will open on most computers, I don't know what's stopping yours from opening it.
I don't think it would take that long to copy the whole thing. You could then email it to your computer.
Getting started
Learning objectives
After this section
- You will have written and executed your first Python program
- You will know how to use the print command
- You will be able to use programming for arithmetic operations
Computer programs consist of
commands, each command instructing the computer to take some action. A computer executes these commands one by one. Among other things, commands can be used to perform calculations, compare things in the computer's memory, cause changes in how the program functions, relay messages or ask for information from the program's user.
Let's begin programming by getting familiar with the print command, which
prints text. In this context, printing essentially means that the program will show some text on the screen.
The following program will print the line "Hi there!":
print("Hi there!")
When the program is run, it produces this:
Sample output
Hi there!
The program will not work unless the code is written exactly as it is above. For example, trying to run the print command without the quotation marks, like so
print(Hi there!)
will not print out the message, but instead causes an error:
Sample output
File "", line 1
print(Hi there!)
^
SyntaxError: invalid syntax
In summary, if you want to print text, the text must all be encased in quotation marks or Python will not interpret it correctly.
Programming exercise:
Emoticon
Points:
/
Please write a program which prints out an emoticon:
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A program of multiple commands
Multiple commands written in succession will be executed in order from first to last. For example this program
print("Welcome to Introduction to Programming!")
print("First we will practice using the print command.")
print("This program prints three lines of text on the screen.")
prints the following lines on the screen:
Sample output
Welcome to Introduction to Programming! First we will practice using the print command. This program prints three lines of text on the screen.
Programming exercise:
Fix the code: Seven Brothers
Points:
/
"Seitsemän veljestä" is one of the first novels ever written in Finnish. It is the story of seven orphaned brothers learning to make their way in the world (
read more on Wikipedia).
This program is supposed to print out the names of the brothers in alphabetical order, but it's not working quite right yet. Please fix the program so that the names are printed in the correct order.
print("Simeoni")
print("Juhani")
print("Eero")
print("Lauri")
print("Aapo")
print("Tuomas")
print("Timo")
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Programming exercise:
Row, Row, Row Your Boat
Points:
/
Please write a program which prints out the following lines exactly as they are written here, punctuation and all:
Sample output
Row, row, row your boat, Gently down the stream. Merrily, merrily, merrily, merrily, Life is but a dream.
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Arithmetic operations
You can also put arithmetic operations inside a print command. Running it will then print out the result of the operation. For example, the following program
print(2 + 5)
print(3 * 3)
print(2 + 2 * 10)
prints out these lines:
Sample output
7 9 22
Notice the lack of quotation marks around the arithmetic operations above. Quotation marks are used to signify
strings. In the context of programming, strings are sequences of characters. They can consist of letters, numbers and any other types of characters, such as punctuation. Strings aren't just words as we commonly understand them, but instead a single string can be as long as multiple complete sentences. Strings are usually printed out exactly as they are written. Thus, the following two commands produce two quite different results:
print(2 + 2 * 10)
print("2 + 2 * 10")
This program prints out:
Sample output
22 2 + 2 * 10
With the second line of code, Python does not calculate the result of the operation, but instead prints out the operation itself, as a string. So, strings are printed out just as they are written, without any reference to their contents.
Commenting
Any line beginning with the pound sign #, also known as a hash or a number sign, is a comment. This means that any text on that line following the # symbol will not in any way affect how the program functions. Python will simply ignore it.
Comments are used for explaining how a program works, to both the programmer themselves, and others reading the program code. In this program a comment explains the calculation performed in the code:
print("Hours in a year:")
# there are 365 days in a year and 24 hours in each day
print(365*24)
When the program is run, the comment will not be visible to the user:
Sample output
Hours in a year: 8760
Short comments can also be added to the end of a line:
print("Hours in a year:")
print(365*24) # 365 days, 24 hours in each day
Programming exercise:
Minutes in a year
Points:
/
Please write a program which prints out the number of minutes in a year. Use Python code to perform the calculation, as in the previous code example.
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Programming exercise:
Print some code
Points:
/
Thus far, you have probably used double quotation marks " to print out strings. In addition to the double quotation marks, Python also accepts single quotation marks '.
This comes in handy if you ever want to print out the actual quotation marks themselves:
print('"Come right back!", shouted the police officer.')
Sample output
"Come right back!", shouted the police officer.
Please write a program which prints out the following:
Sample output
print("Hello there!")
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You have reached the end of this section! Continue to the next section:
2. Information from the user
