字符類匹配一組字符中的任何一個。下表描述了字符類：

字符類	描述	模式	匹配
[character_group]	匹配character_group任何單個字符。默認情況下，匹配是區分大小寫的	[mn]	"m" 在 "mat"中； "m", "n" 在 "moon" 中
[^character_group]	取反：匹配任何單個字符不在character_group。默認情況下，在character_group的字符是區分大小寫的	[^aei]	"v", "l" 在 "avail" 中
[ first - last ]	字符範圍：匹配範圍是從第一個到最後任何單個字符	(w+)	"Name ", "Addr " 在 "Name Addr " 中
.	通配符：匹配任何單個字符，除了 .	a.e	"ave" 在 "have" 中；"ate" 在 "mate" 中
p{ name }	匹配由指定的Unicode通用類彆的任何單個字符或命名塊 name.	p{Lu}	"C", "L" 在 "City Lights" 中
P{ name }	Matches any single character that is not in the Unicode general category or named block specified by name.	P{Lu}	"i", "t", "y" in "City"
w	Matches any word character.	w	"R", "o", "m" and "1" in "Room#1"
W	Matches any non-word character.	W	"#" in "Room#1"
s	Matches any white-space character.	ws	"D " in "ID A1.3"
S	Matches any non-white-space character.	sS	" _" in "int __ctr"
d	Matches any decimal digit.	d	"4" in "4 = IV"
D	Matches any character other than a decimal digit.	D	" ", "=", " ", "I", "V" in "4 = IV"