Errata for Head First Programming
Submit your own errata for this product.
The errata list is a list of errors and their corrections that were found after the product was released. If the error was corrected in a later version or reprint the date of the correction will be displayed in the column titled "Date Corrected".
The following errata were submitted by our customers and approved as valid errors by the author or editor.
Color Key: Serious Technical Mistake Minor Technical Mistake Language or formatting error Typo Question Note Update
| Version |
Location |
Description |
Submitted By |
Date Submitted |
Date Corrected |
| Printed, PDF, ePub, Mobi, Safari Books Online, Other Digital Version |
chapter 2 "Beans’R’Us" |
chapter 2 "Beans’R’Us"
URL no longer exists
http://www.beans-r-us.biz/prices-loyalty.html
Note from the Author or Editor:
The solution to this is well documented on the O'Reilly forum page for the book. The .biz site has not been active for quite some time, and the eBook and recent reprints have been undated to use beans-r-us.appspot.com instead (beans.itcarlow.ie also works).
--Paul. |
Sophia |
Feb 16, 2016 |
|
| Printed |
Page 39
Program code in it's current form line 3 |
Address line is "http://www.beans-r-us.biz/prices.html" on page 39.
IDLE Illustration on page 40 drops the "www." in the URL address. With the www in the address the results are different then the results in the Python Shell illustration on page 40. I think the code on page 39 should have the URL address = "http://beans-r-us.biz/prices.html" without the "www."
Note from the Author or Editor:
I've tried it both ways and it makes no difference. But, yes, the code in the illustration should match the code in the book. But, as I said, with or without the "www" prefix is working for me. |
bill |
May 12, 2010 |
Jul 12, 2013 |
| Printed, PDF, ePub, Mobi, Safari Books Online, Other Digital Version |
Page 39
first illustration |
the site address: "http://www.beans-r-us.biz/prices.html" takes me to godaddy.com I found a very different site and had to work to find a solution, here's my code:
import urllib.request
page = urllib.request.urlopen("http://ycharts.com/indicators/world_coffee_arabica_price")
text = page.read() .decode("utf8")
#price = text .index("<div id="pgNameVal">")
#p = text .index("pgNameVal") encontramos el indice de una cadena unica
#y contigua a lo que nos interesa
#buscando en el codigo html
#print (p) imprimimos ese indice, contamos caracteres en el sitio para
#averiguar cuanto sumarle a p
#price = (p+?) nos da el caracter de inicio, contamos hasta donde queremos
#imprimir y lo sumamos a p+1, esto nos da el caracter final
price = text[8747:8773]
print (price)
Note from the Author or Editor:
That URL no longer exists. Please see this forum entry for an explanation:
http://forums.oreilly.com/topic/88296-do-not-use-beans-r-usbiz/ |
Eduardo Lopez |
Sep 21, 2013 |
|
| Printed, PDF, ePub, Mobi, Safari Books Online |
Page 42
4th Answer |
(Using an ePub, so I'm not sure the page number will help.) This typo is in the very first "There Are No Dumb Questions" segment in section 1.
In the last line of the answer to the question, "There seems to be many different versions of Python. Which should I use?" the word "deciding" is misspelled "decidiing", with two 'i's.
Note from the Author or Editor:
Yes, this is a typo. Please change "decidiing" to "deciding" at the bottom of column 1 on page 9 (of the PDF/book). |
Anonymous |
Jul 24, 2014 |
|
| Printed, PDF, Safari Books Online |
Page 48
3rd paragraph |
"Goethe" instead of "Geothe"
Note from the Author or Editor:
Change "Geothe" to read "Goethe" under the second Head FIrst paragraph. |
Anonymous |
Oct 03, 2011 |
Jul 12, 2013 |
| Printed |
Page 49
Last bullet point, bottom of the page. |
The bullet point reads:
"Subtract the second index from the first to work out how long the substring should be."
It should read:
"Subtract the first index from the second to work out ...."
As an example of the error:
If the substring were, s[10:25], then subtracting the second index from the first would produce a substring with a negative length (in this case, -15)!
Note from the Author or Editor:
Yes, you are correct. We got the order wrong on page 49 ... thankfully it is OK on page 44. Thanks for this. --Paul. |
Harvey |
Jan 06, 2010 |
Jul 12, 2013 |
| Printed, PDF, Safari Books Online |
Page 51
Paragraph "The price moved" |
"... more dynamic than ..." instead of "... more dynamic that ..."
Note from the Author or Editor:
Change "dynamic that" to "dynamic than". |
Anonymous |
Oct 03, 2011 |
Jul 12, 2013 |
| Printed, PDF, ePub, Mobi, Safari Books Online, Other Digital Version |
Page 61- 62
Code Magnets |
In the magnets exercise and solution, the code won't run unless you write:
while float(price) > 4.74
instead of:
while price > 4.74
Note from the Author or Editor:
Yes, the value of price needs to be converted to a float prior to doing the comparison. See the same code (for page 73) available on the headfirstlabs.com website for this book for another way to do this. |
Aliza |
Dec 21, 2014 |
|
| Printed |
Page 67
The code throughout the rest of chapter 3 |
The code switches back from the loyalty pricing page to the regular pricing page for the rest of the chapter. The regular pricing is too high for the while loop to ever finish. The loyalty pricing properly completes the loop randomly.
Note from the Author or Editor:
The URL used on pages 67, 71 and 73 should be "prices-loyalty.html", not "prices.html" as shown. |
Onelow |
Aug 04, 2010 |
Jul 12, 2013 |
| Printed, PDF, ePub, Mobi, Safari Books Online, Other Digital Version |
Page 70
near bottom |
time.timezone, which does not employ parentheses, reports in seconds, not hours
Note from the Author or Editor:
Last item on list. Remove the parens from "time.timezone()" and replace the word "hours" with the word "seconds" in the description. |
Anonymous |
Sep 19, 2012 |
Jul 12, 2013 |
| Printed |
Page 86
83-85,87 |
The float function is taken out of the example code for the get_price function listed on the pages both before and after the program listed on page 86
Note from the Author or Editor:
Yes, the code for the get_price() function on page 86 should convert the price found to a float using the float() BIF, so as to allow for it's use within calculations within the calling code (as shown on page 90 and subsequent pages). |
Onelow |
Aug 04, 2010 |
|
| Printed |
Page 88
The answer to the 4th question |
"prgrammers" should be "programmers"
|
Dawn |
Apr 21, 2010 |
Jul 12, 2013 |
| Printed, PDF, Safari Books Online |
Page 93
2nd paragraph |
Twitter say that from 16th August they no longer support basic authentication.
Is there any advice on how this code can be modified?
Note from the Author or Editor:
The solution to this Twitter change of policy is, thanks to David, "fixed" here: http://forums.oreilly.com/content/Head-First-Programming/20756/Sending-Messages-To-Twitter/ |
Fraser |
Aug 21, 2010 |
Jul 12, 2013 |
| Printed, PDF, ePub, Mobi, Safari Books Online |
Page 93
send_to_twitter() figure |
The figure here (which I think is the result of the previous erratum for page 93) doesn't send "I am a message that will be sent to Twitter" as shown on page 94. Instead it already incorporates the parameterization that's the task of the Sharpen Your Pencil on pages 97-98.
Note from the Author or Editor:
Yes, we appear to be ahead of ourselves here. Noted this to be fixed in 2nd edition. |
Christopher Bohn |
Aug 04, 2013 |
|
| PDF |
Page 111
Programming Tools section, 7th point |
|
Erik Weibust |
Jun 10, 2010 |
Jul 12, 2013 |
| Safari Books Online |
128
In Sharpen Your Pencil box |
"You were think about what would make the program easier to"
should read
You were thinking...
Note from the Author or Editor:
Should read "You were to think..." - this is an issue in the printed book, too. |
Cathy Austin |
Apr 06, 2010 |
Jul 12, 2013 |
| Safari Books Online |
154
"In Take each of the keys in the hash in turn" pointer |
for key in scores. keys() :
print( scores[key] + ' had a score of ' + str(name_part) )
***name_part is not defined. It should be:***
for key in scores. keys() :
print( scores[key] + ' had a score of ' + str(key) )
Note from the Author or Editor:
The suggested fix is the correct code to use. Thanks. |
Cathy Austin |
Apr 06, 2010 |
Jul 12, 2013 |
| Printed |
Page 167
In the "Do this!" box |
"Be sure to put the function near the top of *you* file" should be "Be sure to put the function near the top of *your* file"
|
Dawn |
Apr 21, 2010 |
Jul 12, 2013 |
| Printed, PDF, Safari Books Online |
Page 182
Sharpen your pencil Answer |
Explanatory comment about the Credit card length should point to the first "%16s" not the last which formats the Description.
Note from the Author or Editor:
Correct - the arrow is pointing to the wrong %16s. |
Fraser |
Aug 23, 2010 |
Jul 12, 2013 |
| Printed |
Page 183
Third line of code from the top of the page. |
On p. 182, the format string we were to create appears thus:
"%16s%07d%16s\n" % (credit_card, price * 100, description).
On p. 183, however, we are told that the following is the string that we just created (the one that we're supposed to use in the code):
"%s%07d%s\n" % (credit_card, price * 100, description).
The second version is missing both instances of the sixteen-character padding formatting element. The result of this is that, in the transactions file, the description is not separated from the price by any spaces.
Note from the Author or Editor:
Change the code on 183/184 from:
%s%07d%s\n
to:
%16s%07d%s\n" |
Harvey |
Jan 15, 2010 |
Jul 12, 2013 |
| Printed |
Page 194 ff
Various places. |
The following error is one of inconsistency (but it's trivial).
In chapter six the price of a latte is $2.0, until you get to p. 194. Beginning on p. 194, and for the rest of the chapter, the price of a latte is $2.20.
|
Harvey |
Jan 15, 2010 |
|
| Printed, PDF, Safari Books Online |
Page 212
Both sample transaction printouts |
The braces for the comment have slipped sideways so instead of marking the price, they include the first digit of the credit card number.
Note from the Author or Editor:
Yes - they need to move to the left a little bit in two places (in both diagrams). |
Fraser |
Aug 23, 2010 |
Jul 12, 2013 |
| Printed |
Page 255
The "Python Tools" section |
In the "Python Tools" section appearing at the end of chapter seven, we are told that we covered Python's "break" statement. This is incorrect: the "break" statement is NOT covered in chapter seven.
Note from the Author or Editor:
This is correct. The "break" statement is NOT covered in Chapter 7 (or anywhere else from what I can see). Well spotted. Thanks. |
Harvey |
Jan 23, 2010 |
Jul 12, 2013 |
| Printed |
Page 288
Bottom of the save_data() function |
Near the end of the save_data() function, the following line appears twice: description.delete(0, END). It should appear once, only.
Note from the Author or Editor:
Yes, that's a typo. Only one of those statements is needed. |
Harvey |
Jan 24, 2010 |
Jul 12, 2013 |
| Printed |
Page 296 ff.
All of Chapter Eight |
In my previous errata submission I pointed out the following typo:
"Near the end of the save_data() function, the following line appears twice: description.delete(0, END). It should appear once, only."
I have discovered that this typo is repeated in every occurrence of the "save_data()" function that appears in chapter eight. It occurs seven times.
Note from the Author or Editor:
Remove one of the duplicate lines. |
Harvey |
Jan 25, 2010 |
Jul 12, 2013 |
| Printed |
Page 341
first column |
the first answer was talking about typos and there was actually a typo. “As using the word “from” makes a lot of sense when taking about a scale” (probably should be talking). If that was intentional, you got me…
|
David Griffiths
|
Jan 04, 2010 |
Jul 12, 2013 |
| Printed |
Page 357
2nd para |
"checkoxes" should be "checkboxes"
|
David Griffiths
|
Jan 04, 2010 |
Jul 12, 2013 |
| Printed |
Page 360
Near bottom of code |
The code from this page on uses "track.stop()" in the shutdown() function. It should read "mixer.stop()". The code on the book's website reflects this change, however, the printed book does not. Also an issue on page(s) 374, 379 and 380.
|
Paul Barry
|
Feb 16, 2010 |
Jul 12, 2013 |
|
