Category: Technical

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.

Mac Gatekeeper Error

This is an update of a post that originally appeared on March 21, 2016.

A number of my books ask readers to download an IDE or other code and install it on their Mac systems. The problem is that the Mac system won’t always cooperate. For example, you might see an error dialog like the one shown for Code::Blocks:

The Gatekeeper error tells you that it won't allow you to install software from unknown publishers.
Your Mac won’t let you install software.

The problem is one of permissions. The default permissions set for newer Mac systems restrict you to getting your apps from the Mac App Store or from vendors who have signed their files. Fortunately, you can overcome this problem either temporarily or permanently, depending on how you want to use your Mac. The blog post What is Gatekeeper & How to Disable Gatekeeper on Monterey? provides you with illustrated, step-by-step directions to perform the task using either method. Let me know if you encounter any other problems getting your Mac to install the software required to use my books at [email protected].

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.

Introducing Machine Learning Security Principles

Are you a manager, researcher, or novice data scientist who works with data regularly, yet can’t really understand the technobabble found in security books that are supposed to help you secure the data you work with? Machine Learning Security Principles is all about providing you with full disclosure of all of the security threats that can affect your data in a detailed way that is also understandable. The idea is to understand the threats and understand the players in the security arena so you can create a strategy that will ensure your data remains safe without feeling completely lost in the language used by most books today.

Machine Learning Security Principles looks at data from every possible perspective, which means that you’ll learn more than just collection and storage methods. It isn’t just the hackers and disgruntled employees that are the problem. You now have to deal with governments that tell you how to collect data properly and face the wrath of the pubic at large when the data is collected in a less than ethical manner, even when no laws have been broken. In addition, it’s more than just the data, it’s also the system that holds the data, the application the uses the data, and the users who enter the data that can become problematic. With this in mind, here are some things that you’ll learn when reading this book:

  • Learn methods to prevent illegal access to your system.
  • Discover detection methods when access does occur.
  • Employ machine learning techniques to determine motivations.
  • Mitigate hacker access using a variety of methods.
  • Repair damage to your data and applications.
  • Use ethical data collection methods to reduce security risks.

A major complaint with most books on the market is that there is an expectation that you’re not only an expert coder, but that all you want is to see code. That’s fine if you’re already a seasoned security expert, but then seasoned security experts really don’t need books like this one. Machine Learning Security Principles provides you with several ways to learn about security issues:

  • References to actual security break-ins and the results of them.
  • Block diagrams showing how various kinds of security issues occur.
  • Explanatory text that helps you understand what precisely can happen and how to prevent.
  • Example code that you can use to discover how various security techniques work.
  • Example data and the techniques you can use to work with it.
  • Resources that you can use to augment your security plan.
  • Online tools you can use to more fully explore security issues.

In short, Machine Learning Security Principles provides you with several methods of learning about security in an easy to use manner. It doesn’t take a one size fits all approach. Please let me know if you have any questions about my new book by contacting me at [email protected].

Spaces in Paths

This is an update of the previous post originally created on April 20, 2016.

A number of readers have recently written me about an error they see when attempting to compile or execute an application or script in books such as, C++ All-In-One for Dummies, 4th Edition, Beginning Programming with Python For Dummies, 2nd Edition, Python for Data Science for Dummies, and Machine Learning for Dummies, 2nd Edition. Development environments often handle spaces differently because they’re designed to perform tasks such as compiling applications and running scripts. When you see an error message that tells you that a file or path isn’t found, you need to start looking at the path and determine whether it contains any spaces. The best option is to create a directory to hold your source code and to place that directory off the root directory of your drive if at all possible. Keeping the path small and simple is your best way to avoid potential problems compiling code or running scripts.

The problem for many readers is that the error message is buried inside a whole bunch of nonsensical looking text. The output from your compiler or interpreter can contain all sorts of useful debugging information, such as a complete listing of calls that the compiler, interpreter, or application made. However, unless you know how to read this information, which is often arcane at best, it looks like gobbledygook. Simply keep scanning through the output until you see something that humans can read and understand. More often than not, you see an error message that helps you understand what went wrong, such as not being able to find a file or path. Please let me know if you ever have problems making the code examples in my books work, but also be sure to save yourself some time and effort by reading those error messages. Let me know if you have any thoughts or concerns about spaces in directory paths at [email protected].

Damaged Books

I spend a good deal of time reviewing comments about my books online and also responding to reader questions sent to my email. It’s important to me that you feel you receive the full value of your hard earned money when buying one of my books, so I continually seek to improve them. However, one issue I can’t control is the damaged book. When reading one series of comments lately, I found that the readers weren’t complaining about the quality of the content, but rather the quality of the book materials, which is not something I can control.

The problem is made worse because I often have no way to contact readers who leave a comment on places like Amazon.com. In the interest of customer privacy, I’m unable to obtain an email address for these readers so that I might address their needs. This is why you should always contact me at [email protected] when you have any issues with my books.

The publisher isn’t able to obtain your email address either. So, the publisher is equally unable to help you when you post a book material complaint on websites, rather than contact the publisher. One of the publishers I work with most often is Wiley. Here is the advice I received from my editor there regarding book damage:

In cases of damage or misprinting, it depends on the specific issue, cause of the damage, and the seller whether Wiley can replace a copy or not. For example, if purchased from a third-party seller on Amazon and damaged in transit, that’s out of our control, as third-party sellers are not direct partners or buyers from Wiley. If it’s a printing issue like this one [referring to spotting in one of my books], that is a manufacturing issue within our control, and Wiley would very likely replace the copy. Here is a link customers can visit https://support.dummies.com/s/. They can also email [email protected].

In cases of possible errata: The readers should fill out an Errata PDF form available here: https://support.dummies.com/s/article/reporting-a-wiley-book-error and email it to the Customer Service Team at [email protected] with the subject line “Possible Book Errata Submission”.

The bottom line is that the publisher and I want you to be happy. Make this possible by contacting us about any book damage, rather than posting a public comment that we can’t address.

Get the Source Code for My Books from Another Source

A lot of readers have asked me to provide a better, centralized, location for the source code for my books. With this in mind, I’ve created a new Source Code web page on my website. All you need to do to use it is locate the name of the book whose source code you need and click the associated link or Download button. Not all of my books appear on the Source Code page yet, but I’m working on it. If you find that you can’t locate a book you desperately need, please let me know at [email protected]. I’ll do my best to help you make great use of my books. Please continue to frequent this blog for updates and news about my books.

C++ All-in-One for Dummies Errata on Page 188

There is a mistake on page 188 of C++ All-in-One for Dummies, 4th Edition that is based on a supposed April Fool’s prank that was actually initiated on March 26, 2018 (see https://www.modernescpp.com/index.php/no-new-new) and spread throughout the Internet to sites such as: https://www.fluentcpp.com/2018/04/01/cpp-will-no-longer-have-pointers/.  The problem with pranks, especially pranks that linger because the people who perpetuate them haven’t removed them, is that other people tend to believe them, as in this post: https://stackoverflow.com/questions/59820879/are-new-and-delete-getting-deprecated-in-c#. Later, much later, as in the note on the Fluent C++ site, people admit that it was a joke, but still leave the errant material in place.

 After I had discovered that this information was a joke, I had meant to remove two sentences from the book, but somehow they stayed intact.  The two sentences in question appear in the “Understanding the Changes in Pointers for C++ 20” section:

Readers who already know something about pointers need to be aware of the changes in pointers for C++ 20, which is why it appears first. The essential thing to remember as you move to C++ 20 (where new is deprecated) and then to C++ 23 (where new is removed) is that pointers are going to change.

If you find any other references in the book that state that new is deprecated or removed, they too will be modified or eliminated during the next printing. I apologize for any problems that the error has caused, especially to readers who are new to C++, and have submitted an errata to the publisher so that the error is fixed during the next printing. If you have any questions at all about the book, please contact me at [email protected].

Completed! Book Drawing for C++ All-in-One for Dummies, 4th Edition

Five people now have a copy of C++ All-in-One for Dummies, 4th Edition coming their way. Please wait four to six weeks for delivery and let me know when you receive your book. These people are:

  • Eva Beattie
  • Thomas McQuillan
  • Michael Flores
  • Syam Poolla
  • Tom Taylor

I hope that each of you enjoys the book and will provide a review of it on Amazon. Thank you for your support, it’s really important to me. Your reviews will help other readers as well. If you have any questions at all about the book, please contact me at [email protected].