Python 50 serial greedy matching, XPath Introduction

First, greed and non-greed

1. Greed: as many matches (*) represents the greedy match

2. Non-greedy: (?) To find qualified to a minimum content, represents a non-greedy

3. Regular default greedy match

 

import re

title = u"<div>name</div><div>age</div>"

p1 = re.compile(r"<div>.*</div>")#贪婪模式

p2 = re.compile(r"<div>.*?<div>")#非贪婪模式

m1 = p1.search(title)

print(m1.group())



m2 = p2.search(title)

print(m2.group())

Two, XPATH

1. Interpretation: Find a set of rules of information / language in the XML file, the XML elements

Documentation help: http: //www.w3cshool.com.cn/xpath/index.asp

2.XPath Development Tools

Open source XPath expression editing tools: XMLQuire

Chrome plug-in: XPath Helper

Firefox plug-in: XPath Checker

3. how to select nodes in an XML file

(1) nodename: Select all the child nodes of this node

(2) /: Start from the root node to select

Examples: / Student: No results

/ School: School selected node

(3) @: select nodes, without considering the position

Examples: // age: selecting three nodes, generally consisting of a list of return

(4) Select the current node .:

(5) ..: Select the parent node of the current node

(6) @: selection attribute

(7) Xpath find general method to find a path in accordance with

School / teacher: teacher returned node

School / student: student returns two nodes

// Student: Student Select all nodes, regardless of location

School // Age: select all nodes Age School offspring

// @ Other: Select Other property

// Age [@Details]: Select an element with attributes Details of Age

<?xml version="1.0" encoding="utf-8" ?>

<School>

    <Teacher desc="PythonTeacher" score="good">

        <name>LiuDana</name>

        <Age_1 Details="Age for year 2010">18</Age_1>

        <Mobile>13260446055</Mobile>

    </Teacher>

    <Student>

        <zhangsan>= "He is a squad leader"OtherThe Name</Name>

        <Age Details="The youngest boy in class">14</Age>

    </Student>

    <Student>

        <Name>LiSi</Name>

        <Age>19</Age>

        <Mobile>15578875040</Mobile>

    </Student>

</School>

4. predicate

/ School / Student [1]: Select School following a first node Student

/ School / Student [last ()]: Select School Student following the last node

/ School / Student [last () - 1]: Select School Student following penultimate node

/ School / Student [position () <3]: Select the first two nodes below School

// Student [@score]: Select Student score of nodes with attributes

// Student [@ score = "99"]: Select score with attributes and attribute values of Student nodes 99

// Student [@score] / Age: Age Student selected child node score of nodes with attributes

Some operations in 5.XPath

(1) |: or

For example: // Student [@score] | // Teacher: selecting nodes with attributes Student or Teacher node score

(2) The remaining not common XPath arithmetic symbol + .-. *, Div (division means),>, <

Second, the source

D31_2_GreedMatch.py

D32_1_School.xml

https://github.com/ruigege66/Python_learning/blob/master/D31_2_GreedMatch.py

https://github.com/ruigege66/Python_learning/blob/master/D32_1_School.xml

2.CSDN: https: //blog.csdn.net/weixin_44630050 (Xi Jun Jun Moods do not know - Rui)

3. Park blog: https: //www.cnblogs.com/ruigege0000/

4. Welcomes the focus on micro-channel public number: Fourier transform public personal number, only for learning exchanges, backstage reply "gifts" to get big data learning materials

Python 50 serial greedy matching, XPath Introduction

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