Python in a Nutshell

Errata for Python in a Nutshell

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
Page 21

The Meaning of the -tt option reads: "Like -tt, but raises an error rather than a warning" now reads: "Like -t, but raises an error rather than a warning" p. 45 -- "from future import division" now reads: "from __future__ import division"

Anonymous    Sep 01, 2003
Printed
Page 47
Pargraph "Slicing a sequence", lines 4-5

"j is less than i" now reads: "j is less than or equal to i"

Anonymous    Sep 01, 2003
Printed
Page 48
Modifying a list, 2nd bulleted item

L[i:i]=['a','b'] inserts the items 'a' and 'b' after item i in L. now reads: L[i:i]=['a','b'] inserts the items 'a' and 'b' before item i in L.

Anonymous    Sep 01, 2003
Printed
Page 48
Last paragraph

The last sentence ends with "..., while L*=n has the effect of adding n copies of L to the end of L." The last sentence now reads: "..., while L *= n has the effect of adding n-1 copies of L to the end of L."

Anonymous    Sep 01, 2003
Printed
Page 48
"Modifying a list", first code fragment

x[1] = 42 # x is now [1,42,2,3] Now reads: x[1] = 42 # x is now [1,42,3,4]

Anonymous    Sep 01, 2003
Printed
Page 52
IN PRINT: "The if Statement", syntax listing

"else expression: statement(s)" Now reads: "else: statement(s)"

Anonymous    Sep 01, 2003
Printed
Page 65
last code listing

def percent2(a, b, c): #needs 2.2 or "from future import" Now reads: def percent2(a, b, c): #needs 2.2 or "from __future__ import"

Anonymous    Sep 01, 2003
Printed
Page 66
2nd code listing

def make_adder_2(augend): # needs 2.2 or "from future import" Now reads: def make_adder_2(augend): # needs 2.2 or "from __future__ import"

Anonymous    Sep 01, 2003
Printed
Page 76
middle of page

print x.e, x.d, x.c, x.b. x.a NOW READS: print x.e, x.d, x.c, x.b, x.a

Anonymous    Aug 01, 2004
Printed
Page 78
2nd paragraph, first sentence

Missing "to" in "A bound method is similar TO an unbound method,..." has now been added.

Anonymous    Sep 01, 2003
Printed
Page 85 & 86
code examples

The code samples use the variable "heigth", which is now correctly spelled as "height".

Anonymous    Sep 01, 2003
Printed
Page 86
middle of the page

The code: class OptimizedRectangle(object): __slots__ = 'width', 'height' __slots__ cannot usefully be added by inheritance in this way; so the example should be rewritten to avoid inheritance and rather just copy the whole Rectangle class as given at the top of page 85 under the new name OptimizedRectangle: class OptimizedRectangle(object): __slots__ = 'width', 'height' def __init__(self, width, height): self.width = width self.height = height def getArea(self): return self.width * self.height area = property(getArea, doc="area of the rectangle")

Anonymous   
Printed
Page 100
IN PRINT: Single line of code near bottom of page

"__metaclass_ = type" Now reads: "__metaclass__ = type"

Anonymous    Sep 01, 2003
Printed
Page 100
Last sentence, 5th paragraph

"Since type(object) is type, a class C that inherits from object (or some other built- in type) gets the same metaclass as object (i.e., type(C), C's metaclass, is also type) Thus, being a new-style class is synonymous with having type as the metaclass." "Thus, being..." is the start of a second sentence. A period HAS BEEN ADDED to the end of the sentence "Since type(object)...".

Anonymous    Aug 01, 2004
Printed
Page 112
IN PRINT: First code sample, second line

"except InvalidAttribute, err" Now reads: "except InvalidAttribute, err:"

Anonymous    Sep 01, 2003
Printed
Page 130
buffer() function

where it says: For more on buffer, see Chapter 13. The text now reads: The buffer built-in is now deprecated.

Anonymous    Sep 01, 2003
Printed
Page 163
IN PRINT: Code listing near top of page, third line

"if re.search(..." Now reads: "if digatend.search(..."

Anonymous    Sep 01, 2003
Printed
Page 163
Bottom

The bottom line of text was missing in printings after 9/03. the missing line was: want to print only words that are followed by whitespace (not THIS HAS BEEN CORRECTED.

Anonymous    Aug 01, 2005
Printed
Page 164
Description of "map - last paragraph

The last Paragraph of the description of map states:- "When func is None, map returns a list of tuples ..." This is only true if map is given at least 2 seqs to "map". If it is given a single seq, it returns the seq itself. This can cause serious errors in programs that expect tuples to be returned.

Note from the Author or Editor:
p. 164 under `map`, 2nd paragraph, change the text that now reads When func is None, map returns a list of tuples, each with n items (one item from each iterable); this is to read When func is None, map returns a list of tuples, each with n items (one item from each iterable) when n>1; this is and add to the same paragraph (which now ends "the longer ones.") a further sentence When func is None and n is 1, map returns a list of the items of seq (while zip would return a list of tuples with just one item each).

Ross Cartlidge  Jan 29, 2009 
Printed
Page 177
Last paragraph

The os.path Module functions table is missing the "expanduser" method and related description. (See, for example, the documentation at the following URL: http://python.org/doc/2.2.3/lib/module-os.path.html)

Anonymous   
Printed
Page 177
dirname

"For example, os.path.basename('b/c/d.e') returns 'b/c'" Now reads: "For examples, os.path.dirname('b/c/d.e') returns 'b/c'"

Anonymous    Sep 01, 2003
Printed
Page 185
third line from the bottom; the description of lseek

"but calling lstat on a file that does not support seeking ..." should be: "but calling lseek on a file that does not support seeking ..."

Anonymous   
Printed
Page 202
Example code, data_to_zip_direct

To make the example work the same way for both the direct and indirect method, the line: zinfo.compress_type = zipfile.ZIP_DEFLATED HAS BEEN ADDED after the line: zinfo = zipfile.ZipInfo(name, time.localtime()[:6])

Anonymous    Aug 01, 2004
Printed
Page 221
1st paragraph of description of the translation() function,2nd/3rd sentences

When languages is None, translation looks in the environment for the lang to use, like install. However, languages can also be a list of one or more lang names separated by colons (:), in which case translation uses the first of these names for which it finds a .mo file. NOW READS: When languages is None, translation looks in the environment for the lang to use, like install: it examines, in order, environment variables LANGUAGE, LC_ALL, LC_MESSAGES, LANG -- the first non-empty one is split on ':' to give a list of lang names (for example, 'de:en' would be split to give ['de','en']). When not None, languages must be a list of one or more lang names (for example, ['de','en']). Translation uses the first lang name in the list for which it finds an .mo file.

Anonymous    Aug 01, 2005
Printed
Page 222
11th line

gettext.translation(domain, languages=lang) NOW READS: gettext.translation(domain, languages=[lang])

Anonymous    Aug 01, 2004
Printed
Page 225

"in releases of Python older than the ones covered in this book, unpickling from an untrusted data source was a security risk ... No such weaknesses are known in Python 2.1 and later." This is no longer true, the 2nd edition says: Note that unpickling from an untrusted data source is a security risk; an attacker could exploit this to execute arbitrary code. Don't unpickle untrusted data!

Anonymous   
Printed
Page 241
IN PRINT: Connection Objects - cursor method

x.close() Now reads: x.cursor()

Anonymous    Sep 01, 2003
Printed
Page 284
Threading example program at bottom of page

Classes ExternalInterfacing and Serializer (snippets on pages 284-285) are not thread-safe as shown in the book. Change the snippets as follows: Add the following auxiliary class, to be used in both snippets, and useful in its own right: class PoolOfQueues: # thread-safe, because a list's pop and append methods are atomic def __init__(self): self.pool = [] def get_a_queue_from_pool(self): try: return self.pool.pop() except IndexError: return Queue.Queue() def return_a_queue_to_pool(self, q): self.pool.append(q) queues=PoolOfQueues() Change class ExternalInterfacing to: class ExternalInterfacing(Threading.Thread): def __init__(self, externalCallable, **kwds): Threading.Thread.__init__(self, **kwds) self.setDaemon(1) self.externalCallable = externalCallable self.workRequestQueue = Queue.Queue() self.start() def request(self, *args, **kwds): "called by other threads as externalCallable would be" q = queues.get_a_queue_from_pool() self.workRequestQueue.put((q, args, kwds)) try: return q.get() finally: queues.return_a_queue_to_pool(q) def run(self): while 1: q, args, kwds = self.workRequestQueue.get() q.put(self.externalCallable(*args, **kwds)) Change class Serializer to: class Serializer(Threading.Thread): def __init__(self, **kwds): Threading.Thread.__init__(self, **kwds) self.setDaemon(1) self.workRequestQueue = Queue.Queue() self.start() def apply(self, callable, *args, **kwds): "called by other threads as callable would be" q = queues.get_a_queue_from_pool() self.workRequestQueue.put((q, callable, args, kwds)) try: return q.get() finally: queues.return_a_queue_to_pool(q) def run(self): while 1: q, callable, args, kwds = self.workRequestQueue.get() q.put(callable(*args, **kwds))

Anonymous   
Printed
Page 284
IN PRINT: code sample, first line

import Threading, Queue Now reads: import threading, Queue

Anonymous    Sep 01, 2003
Printed
Page 285
IN PRINT: code sample in middle of page, first line

import Threading, Queue Now reads: import threading, Queue

Anonymous    Sep 01, 2003
Printed
Page 286
IN PRINT: first code sample, first line

import Threading Now reads: import threading

Anonymous    Sep 01, 2003
Printed
Page 291
bottom

import os os.spawnv(os.p_WAIT, editor, [textfile]) NOW READS: import os os.spawnv(os.p_WAIT, editor, [editor, textfile]) and, the last sentence NOW READS: The first item of the argument <replaceable>args</replaceable> is passed to the program being spawned as "the name under which the program is being invoked". Most programs don't look at this, so you can place any string there. Just in case the editor program does look at this special first argument, passing the same string <replaceable>editor</replaceable> that is used as the second argument to os.spawnv is the simplest and most effective approach.

Anonymous    Aug 01, 2005
Printed
Page 303
5th paragraph, tofile

tofile Note that f should be open for reading in binary mode, for example with mode 'rb'. now reads: tofile Note that f should be open for writing in binary mode, for example with mode 'wb'.

Anonymous    Sep 01, 2003
Printed
Page 307
Code listing, under Slicing Examples

a[0,2:4) Now reads: a[0,2:4]

Anonymous    Sep 01, 2003
Printed
Page 312
5th paragraph

where it says: an array with rank of one less than a and of the same size as a The text now reads: an array with rank 1 and of the same size as a

Anonymous    Sep 01, 2003
Printed
Page 320
3rd paragraph

where it says: just like array(a,copy=False).flat The text now reads: just like array(a,copy=(not a.iscontiguous())).flat

Anonymous    Sep 01, 2003
Printed
Page 328
the URL

http://starbase.neosoft.com/~claird/comp.lang.python/python_GUI.html The URL has changed and now reads: http://phaseit.net/claird/comp.lang.python/python_GUI.html

Anonymous    Sep 01, 2003
Printed
Page 335
5th paragraph

In the example to diplay GIF images in the example, the line: img.config(image=gifsdict[imgname]) Is now indented as follows: def list_entry_clicked(*ignore): imgname = L.get(L.curselection()[0]) img.config(image=gifsdict[imgname])

Anonymous    Sep 01, 2003
Printed
Page 337
2nd paragraph of Entry section

An Entry instance with state=DISABLED is a good way... "state=DISABLED" should be replaced by "state='readonly'" for the remainder of the page. state=DISABLED doesn't allow you to select an Entry's text or copy it to the clipboard.

Note from the Author or Editor:
p. 416 and 417 *NOT* 337, change all occurrences of DISABLED (I count four) to 'readonly' (lowercase and with single quotes around). So for example state=DISABLED must become state='readonly' and so on.

Anonymous   
Printed
Page 337
last table entry

toggle c.deselect() Now reads: toggle c.toggle()

Anonymous    Sep 01, 2003
Printed
Page 342
middle of page

The entry for 'iconify' shows 'deiconify' for the example. Iconify T.deiconify() Now reads: Iconify T.iconify()

Anonymous    Sep 01, 2003
Printed
Page 346
Under "Menu Example" heading

The following two lines have been added to the end of the script: root.config(menu=bar) Tkinter.mainloop()

Anonymous    Sep 01, 2003
Printed
Page 346
code sample at very bottom

def makeshow(menu): def emit(entry, menu=menu): print menu, entry return emit NOW READS: def mkshow(menu, entry): def emit(): print menu, entry return emit AND the first two lines on the top of page 347; and use command=mkshow('File') and command=mkshow('Edit'), respectively, in the calls to the add_command methods of fil and edi. NOW READ: and use command=mkshow('File', x) and command=mkshow('Edit', x), respectively, in the calls to the add_command methods of fil and edi.

Anonymous    Aug 01, 2004
Printed
Page 361
in plot function

logical error j = CY*(y-miny)/(maxy-miny) Now reads: j = CY - CY*(y-miny)/(maxy-miny)

Anonymous    Sep 01, 2003
Printed
Page 383
second code sample

try: x.f() except AttributeError: sys.stderr.write('x is type %s, (%r) '%(x,type(x))) That 3rd line NOW READS: sys.stderr.write('x is type %s, (%r) '%(type(x), x))

Anonymous    Aug 01, 2004
Printed
Page 421
between mkd and pwd methods

omitted nlist method. The nlst method should probably be included, in its normal alphabetical order (i.e., after mkd but before pwd) with the text (in the usual mixture of fonts and typefaces like for the other methods): nlst f.nlst(pathname='.') Sends a NLST command to the FTP server, asking for the names of the files in the directory named by pathname (by default, the current directory), and returns the list of the filenames. ((i.e., as usual, I would omit weird, rarely used stuff such as, in this case, the optional, non-portable extra arguments)).

Anonymous   
Printed
Page 430
ServerProxy methods

"...supplies an attribute s.server that..." NOW READS: "...supplies an attribute s.system that..." s.server.listMethods() s.server.methodSignature(name) s.server.methodHelp(name) NOW READ: s.system.listMethods() s.system.methodSignature(name) s.system.methodHelp(name)

Anonymous    Aug 01, 2005
Printed
Page 433
fourth and fifth functions (ntohl and ntohs)

where it says ntohl htonl(i32) The text now reads: ntohl ntohl(i32) AND where it says ntohs htons(i32) The text now reads: ntohs ntohs(i32)

Anonymous    Sep 01, 2003
Printed
Page 441
Example code at bottom of page

The example trivial HTTP server is missing the two lines to instantiate and start up the server. After the line do_HEAD = do_POST = do_GET, the following two lines have been added: server = BaseHTTPServer.HTTPServer(('',80), TrivialHTTPRequestHandler) server.serve_forever()

Anonymous    Sep 01, 2003
Printed
Page 445
example 19-6; the final lines of code (at the end of the "for x in i: portion of the example")

try: ous.remove(x) except ValueError: pass x.close() NOW READ: try: ous.remove(x) except ValueError: pass x.close() ins.remove(x)

Anonymous    Aug 01, 2004
Printed
Page 477
2nd par.: MIMEImage

MIMEImage class MIMEAudio(_imagedata,... Now reads: MIMEImage class MIMEImage(_imagedata,...

Anonymous    Sep 01, 2003
Printed
Page 499
last paragraph

quoteattr escape(data,entities={}) Now reads: quoteattr quoteattr(data,entities={}) Pages 507, 508, and 511: The following warning note has been added on page 511: The code examples given on pages 507, 508 and 511 may crash under some version of Python and Windows (not Python 2.3, and not Linux versions of Python). To fix your version of Python so that it is able to run the examples, visit URL: http://sourceforge.net/project/showfiles.php?group_id=6473 and download and run the appropriate self-installing .EXE, for example currently PyXML-0.8.2.win32-py2.2.exe if you run Python 2.2 on any version of Microsoft Windows. This self-installing EXE will add to your Python installation the latest version of the "XML subsystem" of Python, and, as a side effect, fix any bugs connected to XML handling that may have been diagnosed after the release of your version of Python.

Anonymous    Sep 01, 2003
Printed
Page 536
Example 24-1

There are two arrays declared as static char merge_docs[] The second one (page 536) now reads: static char mergenew_docs[] = "

Anonymous    Sep 01, 2003
Printed
Page 567
Manifest section 1st bullet

sdist default does not include scripts or data files, even if specifically mentioned in the setup.py script. The default only includes: "all Python source files implied by the py_modules and packages options" To include scripts or data files by sdist, you have to create a MANIFEST.in

Anonymous   
Printed
Page 569
Bottom paragraph

The Installer website NOW READS: http://www.mcmillan-inc.com/install1.html

Anonymous    Aug 01, 2004
Printed
Page 571
Index of Symbols "*" and "**"

Index for "*" and "**" should be augmented for define extra arguments, 60 pass extra arguments, 64

Anonymous   
Printed
Page 591
bottom right

There is no entry in the index for the consept "frozen", mentioned on page 121 just before and after the heading "Searching the Filesystem for a Module". Worse IMHO, there's no explanation in the book, that I can find, on what "frozen modules" is. A line or two on page 121 would have been nice.

Anonymous