需求：

获取字符串Do you like 2， 3，4 ， 6?中的2， 4， 6

方法：

1. Python

a. Global function

import re

subject = "Do you like 2， 3，4 ， 6?"

result = []

for matchobj in re.finditer(r"\d+",subject):

if int(matchobj.group()) % 2 == 0:

result.append(matchobj.group())

print result

b. Compiled object

import re

subject = "Do you like 2， 3，4 ， 6?"

result = []

reobj = re.compile("\d+")

for matchobj in reobj.finditer(subject):

if int(matchobj.group()) % 2 == 0:

result.append(matchobj.group())

print result

2. Tcl

set subject "Do you like 2， 3，4 ， 6?"

set result ""

set pos 0

while {[regexp -indices -start $pos -linestop {\d+} $subject offsets]==1} {
set pos [expr {1+[lindex $offsets 1]}]

set sTmp[string range $subject [lindex $offsets 0] [lindex $offsets 1]]

if {$sTmp % 2 == 0} {

lappend result $sTmp
}

}

foreach i $result {

puts "$i"

}