Python Learning Notes (group)

In a regular expression, group () is used to present a string that is intercepted by a packet ,() to group

ImportRea="123abc456"PrintRe.search ("([0-9]*) ([a-z]*) ([ 0-9]*)", a). Group (0)#123abc456, return to the wholePrintRe.search ("([0-9]*) ([a-z]*) ([ 0-9]*)", a). Group (1)#123PrintRe.search ("([0-9]*) ([a-z]*) ([ 0-9]*)", a). Group (2)#ABCPrintRe.search ("([0-9]*) ([a-z]*) ([ 0-9]*)", a). Group (3)#456

The reason

1. Three sets of parentheses in regular expressions divide matching results into three groups

• Group () with group (0) is the overall result of matching regular expressions
• Group (1) lists the first bracket matching section, Group (2) lists the second bracket matching part, and group (3) lists the third bracket matching part.

2. No match succeeded, Re.search () return None

Python Learning Notes (group)