Errata

"The date module's time object is used to represent a time of day:" but the code uses the datetime module, not the date module. Sentence should refer to datetime?

Note from the Author or Editor:
I think you're correct, it should refer to datetime. That's what it's imported from.

In the Comprehensions section, when beginning to introduce the ability to use conditional statements, it asks to find odd numbers between one and five. Instead it finds the numbers that when divided by 3, have a remainder of 1 (1 and 4). While this was confusing at first, it was helpful in understanding what that line of code did better.

diagram of union: inner arc shouldn't be there; should be a single unified volume.

diagram of intersection: the intersection should be shaded

Problem 3.12 asks for a dictionary comprehension, but comprehensions aren't discussed until chapter 4.

>>> print(poem2)
I do not like thee, Doctor Fell.
The reason why, I cannot tell.
But this I know, and know full well:
I do not like thee, Doctor Fell.


>>>



The words "not", "and" & "not" are in black when the rest is blue. When I run this using Ipython there is no indent.

A little further down the page the response is in red and blue with "and" & "not" in black

Note from the Author or Editor:
This is an artifact of the PDF production process. The poem text was treated as code, and "not" and "and" are reserved words in Python.

Using a plain : is the same as 0:-1 (the entire string):
letters[:]
'abcdefghijklmnopqrstuvwxyz'

If I use letters[0:-1] it is not the same as letters[:]. It returns 'a-y', while letters[:] returns 'a-z'.

replace() replaces all instances, if count is missing.

If setup = 'a duck goes into a bar...' (p37),

then:
>>> setup.swapcase()

returns:
'A DUCK GOES INTO A BAR...'

not

'a DUCK GOES INTO A BAR...'

Note from the Author or Editor:
Fixed in the third printing.

The example marxes[::2] is shown to display ['Grouch', 'Harpo'] as the value returned. If the user has been following along withthe examples, ['Groucho', 'Wanda'] will be returned. In a previous example Wanda was substituted for Harpo.

Note from the Author or Editor:
Thanks for catching this.I've notified production to add the line to define the marxes list first.

in this example:

>>> marxes = ['Groucho', 'Chico,' 'Harpo']

maybe it should be

>>> marxes = ['Groucho', 'Chico', 'Harpo']

Note from the Author or Editor:
That typo has been fixed in the upcoming edition. Thanks!

Starting at the tenth line of text:

Are all the characters in the poem either letters or numbers?
>>> poem.isalnum
False
Nope, there were some punctuation characters.


Should read >>> poem.isalnum()


Parenthesis missing in the book.

The line: "File "<stdin>", line 2, in change_and_report_it" should read "File "<stdin>", line 2, in change_and_print_global". The function name most likely was changed at some point but the example code was not fully updated.

Note from the Author or Editor:
Fixed in the third printing.

You provide a solution with enumerate()
(for count, number in enumerate(get_odds(), 1):)
but enumerate isn't explained until "Import a Module with Another Name" (Chapter 5)

Note from the Author or Editor:
I changed the answer to example 4.9 and replaced the enumerate() with a counting loop.

The Duck class's about() method refers to "bill.description" and "tail.length". These are the global objects "bill" and "tail", created a little later. To show the values for the "bill" and "tail" attributes of a Duck object, use "self.bill.description" and "self.tail.length".

The book says that the pixel width and height of a GIF are encoded as 16-bit big-endian integers, whereas the GIF specification (and indeed the encoded GIF snippet in the book) suggest they are little-endian 16-bit integers.

This makes this "thing to do" quite confusing, as it left me wondering what I did wrong!

Note from the Author or Editor:
You're correct. Example 7-14 needs to say that the pixel width is a 16-bit little-endian integer. The example solution in Appendix E uses the correct little-endian specifier (<HH), but repeats the wrong information in the question.

The Pattern Matches table at the top of page 153 shows the following:

prev+? one or more prev, as few as possible
prev+? one or more prev, as many as possible

The table actually starts on the previous page (152) where both of the above possibilities are noted. Not to mention that the second is incorrect, I believe. It should read "prev+ one or more prev, as many as possible".

Note from the Author or Editor:
You're right, I had duplicated those two lines. Thanks.

There is an extraneous closing bracket at the end of
fout = open('relativity', 'xt')]

Note from the Author or Editor:
That is a typo. Thanks for catching it.

The byte numbers are wrong. I'm finding this a tricky topic so it's good to get the numbering right for it to make sense. Each dimension (width and height) is represented by four bytes, so the byte sequences should be numbered 16-19 inclusive and 20-23 inclusive. not 16-20 and 21-24.

Note from the Author or Editor:
You're correct. The code is right (exclusive upper bound), but the text incorrectly says they're inclusive.

The exercise 7.14 begins with: "The pixel width of a GIF is a 16-bit big-endian integer". It's wrong, the byte order is little-endian, as can be seen here http://www.onicos.com/staff/iz/formats/gif.html.

Using big endian leads to the wrong result:
>>> struct.unpack('>2H', gif[6:10])
(256, 256)

Using little endian leads to the correct result:
>>> struct.unpack('<2H', gif[6:10])
(1, 1)

Note from the Author or Editor:
The word 'big' has been corrected to 'little' in the text for the third printing. The answer in the appendix has the correct '<' for little-endian.

"...those three values as a list..."

should be

"...those three values as a tuple..."

Using a list seems to work, but the code uses a tuple and the explanation should be consistent.

Note from the Author or Editor:
Corrected in the third printing.

url 'http://www.iheartquotes.com/api/v1/random' does not work anymore.

Note from the Author or Editor:
Another dead free web API! It's hard to find these, since almost all web APIs require registration and a key now. Replaced it with a call to omdbapi.com (a movie search service), which I hope lives longer.

>>> from datetime import date
>>> some_day = date(2014, 7, 4)
>>> fmt = "It's %B %d, %Y, local time %I:%M:%S%p"
>>> some_day.strftime(fmt)
"It's Friday, July 04, 2014, local time 12:00:00AM"

Since there is no "%A: in this "fmt", "Friday" does not appear in the output.

Note from the Author or Editor:
Fixed in the upcoming edition. Thanks!

in the echo function we are returning 'thing' but which will print just the text we use in the url. Further down the page the statement is made that we should see the full 'Say hello to my little friend: ' string but we don't because it is not included in the echo function.

Note from the Author or Editor:
Yes, /echo should just output Godzilla. Looks like I pasted output from the upcining template example.

from flask import Flask, render_template

needs to be

from flask import Flask, render_template, request

Note from the Author or Editor:
Yes, it should have the same imports as the example on the previous page.

The section states "Chapter 1 shows two Python code samples to get information on popular YouTube videos ..."

However, the example in Chapter 1 was changed to the "Wayback Machine" due to the issues you described in that chapter.

Note from the Author or Editor:
That was true in the first two releases (which had the youtube examples), but not in the third, for the reason you stated.

In def dryer(dish_queue) function, `while True` is indented 2 times. It should be indented only once. So as it is now, it should be moved four spaces to the left.

Note from the Author or Editor:
Yep, that's a formatting error. I'll check the corresponding github code.

dryer_thread.start() is indented 8 spaces, but should only be indented 4.

Note from the Author or Editor:
Fixed in the third printing.

In the code for redis_washer.py, num is not defined. I think what you had in mind was dish rather than num.

Note from the Author or Editor:
You are right. Changed 'num' to 'dish' for the third printing.

Sentence reads:

The syntax is timeit.timeit(code, number, count).

I think it should instead say:

The syntax is timeit.timeit(code, number=count).

Note from the Author or Editor:
You are right, and this is now fixed for the third printing.

The link given to install Anaconda 2, http://repo.continuum.io/anaconda3 did not work for me. A quick Google search lead me to http://continuum.io/downloads to get Anaconda.

Note from the Author or Editor:
Fixed for the third printing.

Hello,

The regular expression given for in the answer of the question 7.11 is wrong.

The question is "Find all the words that contain exactly three vowels in a row." And you gave this solution for the regex :
r'\b\w*[aeiou]{3}[^aeiou]\w*\b'

The problem is:
1/ the first \w* can match an infinity of vowels.
2/ the last \w* can match an infinity of vowels.

There's no such word in the testing string called mammoth, but if you add this word 'Squuuuuueeeeeeezze', you'll see that it matches. So the regular expression doesn't work.

Note from the Author or Editor:
You are correct, and this is a good example of incomplete test examples. The pattern should be any number of non-vowels, followed by three vowels, followed by any number of non-vowels.

>>> import re
>>> pat = r'\b[^aeiou]*[aeiou]{3}[^aeiou]*\b'
>>> re.findall(pat, 'abc aaa eeek niiii nooo')
[' aaa ', 'eeek ', ' nooo']