Source Code Placement

This is an update of a post that originally appeared on October 12, 2015.

I always recommend that you download the source code for my books. The Verifying Your Hand Typed Code post discusses some of the issues that readers encounter when typing code by hand. However, I also understand that many people learn best when they type the code by hand and that’s the point of getting my books—to learn something really interesting (see my principles for creating book source code in the Handling Source Code in Books post). Even if you do need to type the source code in order to learn, having the downloadable source code handy will help you locate errors in your code with greater ease. I won’t usually have time to debug your hand typed code for you.

Depending on your platform, you might encounter a situation the IDE chooses an unfortunate place to put the source code you want to save. For example, a Windows System might choose the Program Files folder, which contains a space and doesn’t allow saving of files unless you specifically override the default rights. Fortunately, modern IDEs do manage to avoid many of these problems, but you still need to be aware that they could exist, especially when using an older IDE.

My recommendation for fixing these, and other source code placement problems, is to create a folder that you can access and have full rights to work with to store your source code. My books usually make a recommendation for the source code file path, but you can use any path you want. The point is to create a path that’s:

  • Easy to access
  • Allows full rights
  • Lacks spaces in any of the pathname elements
  • On a local drive, rather than a cloud drive in many cases

As long as you follow these rules, you likely won’t experience problems with your choice of source code location. If you do experience source code placement problems when working with my books, please be sure to let me know at [email protected].

Verifying Your Hand Typed Code

This is an update of a post that originally appeared on January 10, 2014.

I maintain statistics for each of my books that are based on reviews and reader e-mails (so those e-mails you send really are important). These statistics help me write better books in the future and also help me determine the sorts of topics I need to address in my blog. It turns out that one of the most commonly asked questions is why a reader’s hand typed code doesn’t work. Some readers simply ask the question without giving me any details at all, which makes the question impossible to answer. In some cases, the reader sends the hand typed code, expecting that I’ll take time to troubleshoot it. However, this isn’t a realistic request because it defeats the very purpose behind typing the code by hand. If I take the time to diagnose the problems in the code you typed, I’ll be the one to learn an interesting lesson, not you. If you learn better by doing—that is, by typing the code by hand and then running it, then you need to be the one to troubleshoot any problems with the resulting code.

My advice to readers is to use the downloadable source code when working through the book text. If you want to type the code by hand after that as part of your learning experience, at least you’ll know that the example works on your system and you’ll also understand how the example works well enough to troubleshoot any errors in your own code. However, you need to be the one to diagnose the errors. If nothing else, perform a character-by-character comparison of your code to the example code that you downloaded from the publisher’s site. Often, a reader will write back after I suggest this approach and mention that they had no idea that a particular special symbol or method of formatting content was important. These are the sorts of lessons that this kind of exercise provide.

Now, it has happened that the downloadable source code doesn’t always work on a particular user’s system. When the error is in the code or something I can determine about the coding environment, you can be certain that I’ll post information about it on my blog. This should be the first place you look for such information. Simply click on the book title in question under the Technical category. You’ll find a list of posts for that book. Always feel free to contact me about a book-specific question. I want to be sure you have a good learning experience.

There are some situations where a reader tries to run application code that won’t work on a particular system. My books provide information on the kind of system you should use, but I can’t always determine exceptions to the rule in advance. When I post system requirements, your system must meet those requirements because the examples are guaranteed to fail on lesser systems. If you encounter a situation where the downloadable code won’t run on your system, but none of the fixes I post for that code work and your system does meet the requirements, then please feel free to contact me. There are times where an example simply won’t run because you can’t use the required software or the system won’t support it for whatever reason.

The point of this post is that you need to work with the downloadable source code whenever possible. The downloadable source code has been tested by a number of people, usually on a range of systems, to ensure it will work on your system too. I understand that typing the code by hand is an important and viable way to learn, but you should reserve this method as the second learning tier—used after you have tried the downloadable source code. Please let me know if you have any questions or concerns at [email protected].

Working with Code in e-Books

This is an update of a post that originally appeared on March 16, 2016.

Most of my technical readers now use e-books instead of paper books. Of course, there is a convenience factor to storing your entire library on a Kindle, even if it’s a software version of the Kindle. Of course, there are all sorts of e-book formats for your desktop system as well. The point is that electronic format makes a lot of sense when dealing with technical books.

However, e-books can cause some interesting problems and I’ve encountered a few with a number of readers now. The most important consideration is that you can’t cut and paste code from an e-book directly into your IDE and expect it to work. There are all sorts of reasons for this exclusion. For example, cutting and pasting may insert special characters into the output stream or the resulting paste may not have white space in the right places. A common problem is that publishers often convert regular single and double quotes into curly quote equivalents. The two kinds of quotes (both single and double) are completely different and the second type definitely won’t compile.

The best option when working with an e-book is to view the code in the e-book, but still get the downloadable source code for the book from my website or the publisher’s website as described in the book’s introduction. If you can’t find the downloadable source, always feel free to contact me at [email protected]. I want to be sure you have a great reading experience, which means having source code that actually runs in your development environment.

Another potential problem with e-books is that you may see unfortunate code breaks (despite the efforts of the publisher and myself). When you need to understand how white space works with a programming language, always review the downloadable source. The fact that the downloadable source compiles and runs tells you that all the of white space is in the right place and of the correct type. Typing the source code directly out of your e-book could result in added carriage returns or other white space errors that will cause the code to fail, even though the commands, variables, and other parts of the code are all correct.

As always, I’m open to your questions about my books. If you don’t understand how things work, please contact me—that’s why I’m here.

UnZIPping the Downloadable Source

A number of readers have written me to say that they are using the downloadable source and can see the files on their hard drive. However, when they go to access the file using their IDE, the IDE won’t open it. Modern operating systems make things easier for people by displaying the contents of .zip and other archive files as if they’re another directory or folder on the system. However, the IDE doesn’t have the same advantage. You need to remove the files from the .zip archive and place them somewhere on your hard drive that the IDE can locate. You can tell that you’re looking at a .zip file by looking at the path. If you see something like C:\Temp\A4D2E.zip\A4D2E, where A4D2E.zip is the name of the archive, then you know that you’re looking in an archive file. If you still have problems getting the files to open, make sure you remove any spaces from the path that your IDE is using. You can contact me at [email protected] if you have any additional questions about this issue.

Missing Machine Learning for Dummies Downloadable Source Files

A number of people have contacted me to tell me that the downloadable source for Machine Learning for Dummies isn’t appearing on the Dummies site as described in the book. I’ve contacted the publisher about the issue and the downloadable source is now available at http://www.dummies.com/extras/machinelearning. Please look on the Downloads tab, which you can also find at http://www.dummies.com/DummiesTitle/productCd-1119245516,descCd-DOWNLOAD.html and navigate to Click to Download to receive the approximately 485 KB source code file.

When you get the file, open the archive on your hard drive and then follow the directions in the book to create the source code repository for each language. The repository instructions appear on Page 60 for the R programming language and on Page 99 for Python. I apologize for any problems that the initial lack of source code may have caused. If you experience any problems whatsoever in using the source code, please feel free to contact me at [email protected]. Luca and I want to be certain that you have a great learning experience, which means being able to download and use the book’s source code because using hand typed code often leads to problems.

 

Python for Data Science for Dummies Errata on Page 221

The downloadable source for Python for Data Science for Dummies contains a problem that doesn’t actually appear in the book. If you look at page 221, the code block in the middle of the page contains a line saying import numpy as np. This line is essential because the code won’t run without it. The downloadable source for Chapter 12 is missing this line so the example doesn’t run. This P4DS4D; 12; Stretching Pythons Capabilities link provides you with a .ZIP file that contains the replacement source code. Simple remove the P4DS4D; 12; Stretching Pythons Capabilities.ipynb file from the archive and use it in place of your existing file.

Luca and I always want you to have a great experience with our book, so keep those emails coming. Please let me know if you have any questions about source code file update at [email protected]. I’m sorry about any errors that appear in the downloadable source and appreciate the readers who have pointed them out.

 

Python for Data Science for Dummies Errata on Page 124

Python for Data Science for Dummies contains an error in the example that appears on the top half of page 124. In the first of the two grey boxes, the code computes the results of four print statements. The bottom-most print statement, print x[1:2, 1:2], is supposed to compute a result based on rows 1 and 2 of columns 1 and 2, and the bottom grey box seems to confirm that interpretation by the showing the result as [[[14 15 16] [17 18 19]] [[24 25 26] [27 28 29]]]. However, the answer provided for this example in the downloadable source code is [[[14 15 16]]], which doesn’t agree with that in the text.

The good news is that the downloadable source contains the correct code. The error appears only in the book. The last print statement in the book is wrong. Here is the correct code (with output) for this example:

x = np.array([[[1, 2, 3], [4, 5, 6], [7, 8, 9],],
 [[11,12,13], [14,15,16], [17,18,19],],
 [[21,22,23], [24,25,26], [27,28,29]]])

print x[1,1]
print x[:,1,1]
print x[1,:,1]
print
print x[1:3, 1:3]
[14 15 16]
[ 5 15 25]
[12 15 18]

[[[14 15 16]
 [17 18 19]]

[[24 25 26]
 [27 28 29]]]

Please let me know if you have any questions about this example at [email protected]. I’m sorry about the error that appears in the book and appreciate the readers who have pointed it out.

 

Missing XMLData2.xml File

A number of readers have written to report that XMLData2.xml is missing from the downloadable source for Python for Data Science for Dummies. You encounter this file in Chapter 6, on page 108. The publisher has already added the file to the downloadable source, but you might be missing the file from your copy. If so, you can download it by clicking XMLData2.zip. I’m truly sorry about any problems that the missing file might have caused. Please be sure to let me know about your book specific question at [email protected].

 

Browser Support in My Books

A number of my books rely on browser output to show the result of various coding techniques, including Security for Web Developers, HTML5 Programming with JavaScript for Dummies, and CSS3 for Dummies. I try to keep up with changes in technology with my books and I’m currently testing the code in all three books with Internet Explorer 11. According to a recent ComputerWorld article, users of older version of IE only have six weeks to make an update to the new version. They can also use the Edge browser or move to a competitor’s browser. My books list the browsers I used for initial testing of the source code, but I do try to at least check the code with newer browsers to ensure you have a good reading experience. In this case, the check is critical because I can’t expect you to rely on unsupported software to use my books.

When I originally wrote each of these books, I had at least one technical editor and a number of beta readers checking my code under various conditions to ensure the code would run as advertised on the maximum number of systems, we also looked through browser usage statistics such as you’re able to find if you click here, to ensure we enabled the most popular browsers to effortlessly read the books digitally. I no longer have the support, so I’m testing these updates on just my systems. If you encounter a problem with the source code of any of these books, please be sure to contact me at [email protected]. Now, here’s the important part. Make absolutely certain to let me know that you’re using a newer browser-one not originally tested in the book so I can handle your query correctly and also provide an update on my blog. Your input will help other readers.

Whenever possible, I encourage readers to use the environment described in the book to write their own code. Doing so reduces the potential for problems because I know that the environment is tested by a number of people in a number of environments. However, sometimes using the original environment isn’t possible any longer, such as this instance where Microsoft is putting its collective foot down and forcing an update. Please be sure to write me if you have any questions about the source code for these book. Thanks, as always, for your continued support!

 

Missing File from Python for Data Science for Dummies Downloadable Source

A reader recently contacted me regarding a missing file from the downloadable source for Python for Data Science for Dummies. This is the P4DS4D; 01; Quick Overview.ipynb you need for the first chapter. Simply click here to download P4DS4D; 01; Quick Overview.ipynb. I’m also asking the publisher to add the missing file to the downloadable source found on the Dummies site at http://www.dummies.com/store/product/Python-for-Data-Science-For-Dummies.productCd-1118844181,descCd-DOWNLOAD.html. If you encounter any other problems with the book, please be sure to let me know at [email protected]. Thank you for your patience!