Regular Expression Pocket Reference

Errata for Regular Expression Pocket Reference, Second Edition

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Color Key: Serious technical mistake Minor technical mistake Language or formatting error Typo Question Note Update

Version Location Description Submitted by Date submitted
Printed Page 7
Table 1

The entries in Class column should all be lower case.

Kevin Day  Nov 14, 2012 
ePub Page 11,46

page 11: Anchors and zero-width assertions (all languages mentioned in book)

"When supported, \Z matches the end of string or before
a string-ending newline, regardless of match mode."
pg 46, table 1-23 (Python)

Sequence : Meaning
\Z : End of string or before a string-ending newline, in any match mode

The following program, run by python 3.65, shows that \Z (unlike $)
does not match "before a string-ending newline"

import re

if'foo$', 'foo\n'): print("foo\\n matched with $")
if'foo\Z', 'foo\n'): print("foo\\n matched with \Z")

Gregory Sherman  Aug 31, 2018 
Printed, PDF Page 14
Numbers from 0 to 999999

The expression does not match the top string, instead it matched the one below.

Adam Zaremba  Apr 16, 2013 
Printed Page 16
top entry


returns this error: Unbalanced parenthesis

dfolland  Aug 10, 2009 
Printed Page 23
Table 9

I would like to mention the below printing mistakes on page 23 (Table 9).

$' - It should return 'Text after match' (' single quote)
$` - It should return 'Text before match' (` back tick)

Anonymous  Mar 26, 2012 
Printed, PDF Page 27

Under the "meaning" for this class it shows:

"A single character not liste and not contained in a listed range."

Note that it is written as "liste" instead of "listed"  Jun 19, 2011 
PDF Page 39
table 17

\W Nonword character, the Unicode property is the positive \p{Xx) not the negative \P{Xx}

Anonymous  Sep 05, 2012 
Printed Page 68
top of page

The dot will match newline IF the m modifier is used, not the s modifier. In Ruby, it is by default multiline as in other language -- that is, the ^ and $ will match the newline characters in Ruby by default.

In most other languages, the s modifier makes the dot match a newline character. In Ruby, it is the m modifier.

Kin Lum  Nov 16, 2012 
Printed Page 77
supported metacharacters

\t is not a vertical tab..\v is

Peter Lindblom  Sep 11, 2011 
Printed Page 79
inside the sequence-meaning table

"{n}? match at least n times, as few times as possible."
has an error. It has to be {n,}? (with the comma inside the curly brackets).

Anonymous  Aug 09, 2014