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Practical Programming, 3rd Edition
book

Practical Programming, 3rd Edition

by Jennifer Campbell, Jason Montojo, Paul Gries
December 2017
Beginner
412 pages
10h 8m
English
Pragmatic Bookshelf
Content preview from Practical Programming, 3rd Edition

Writing and Running a Program

So far, we have used the shell to investigate Python. As you have seen, the shell will show you the result of evaluating an expression:

​ ​>>>​​ ​​3​​ ​​+​​ ​​5​​ ​​/​​ ​​abs(-2)​
​ 5.5

In a program that is supposed to interact with a human, showing the result of every expression is probably not desirable behavior. (Imagine if your web browser showed you the result of every calculation it performed.)

​How Does a Computer Run a Python Program?​, explained that in order to save code for later use, you can put it in a file with a .py extension. You can then tell Python to run the code in that file rather than type commands in at the interactive prompt.

Here is a program that we wrote using IDLE and saved in a file ...

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Publisher Resources

ISBN: 9781680503036Errata Page