8.2 introduction to common modules 2: xml, configparser, hashlib,

8.2 introduction to common modules 2: xml, configparser, hashlib,
Xml:

Introduction: Contains functions related to the extensible markup language xml

Usage:

• Python has three ways to parse XML--SAX, DOM, and ElementTree, Because xml technology lags behind, so here is not the introduction of sax, dom:

 

Xml text:

<?xml version="1.0"?><data>    <fruit name="apple">        <color>red</color>    </fruit>    <fruit name="banana">        <color>yellow</color>    </fruit>    <fruit name="pine">        <color>unknow</color>    </fruit></data>

Use of ElementTree: import module -- get resolution object -- get node -- operation Node

 

 

# Import xml. etree. elementTree as ET # create the corresponding parsing Object tree = ET. parse ('data. xml ') # obtain the node root = tree. getroot () # Get the root node print (root. tag) # print (root. getchildren () # obtain the child node through iteration. We recommend that you use "for child in root: print (child. tag) # obtain the label print (child. attrib) # obtain the attributes of the child node print (child. text) # Get the text of the child node for cc in child: # Sun Tzu node print (cc. tag) print (cc. attrib) print (cc. text) print ("-----------------") # search for a node by Tag Name: for I in root. findall ('fruit'): # This can only be found at the subnode print (I. tag) print (I. attrib) print (I. text) print ("**********************") for I in root. iter ('color'): print (I. tag) print (I. text) ### search for a node and modify print ("***********************") for I in root. iter ('color'): print (I. text) if I. text = 'unknow': I. text = 'unknowd '# Modify text # Use set: I. set (attribute name, attribute value) tree. write ("data2.xml") # It can be written back to the original file or a new file ### search for a node and delete it for I in root. findall ('fruit'): if I. attrib ['name'] = 'pine': root. remove (I) # Delete the child tree from the parent node. write ("data3.xml") # It can be written back to the original file or a new file ### create a node new_xml = ET. element ("new parent") # create a parent node Note: Only one parent node exists, which is equivalent to creating xmlson_name = ET. subElement (new_xml, "name", attrib = {"att": "yes"}) # create a subnode son_color = ET. subElement (son_name, "color", attrib = {"att": "no"}) son_color.text = 'unknow' name2 = ET. subElement (new_xml, "name", attrib = {"att": "no"}) color2 = ET. subElement (name2, "color") et = ET. elementTree (new_xml) # generate the Document Object et. write ("test. xml ", encoding =" UTF-8 ", xml_declaration = True) # Write the file and determine the format.

 

Configparser:

Introduction: including functions related to configuration files

Initial text content:

[DEFAULT]ip = 192.168.1.1hostname=aotuman[african]color = blackluck = no

Usage:

# Import module import configparser # create a parser con = configparser. configParser () print ("------- read -------------") con. read ('config. ini ') print (con. default_section) # print (con. defaults () # default label result print (con. sections () # print the name of a tag other than the default tag (con ['African '] ['color']) # obtain the corresponding tag attribute print ("------------- write method ------------") con ["DEFAULT"] = {'root': 'yes'} # override con ['Europe'] = {'color': 'white', 'luck ': 'super'} # con ['Europe'] ['LIFE'] = '0' # add style modify with open ('example. ini ', 'w') as configfile: con. write (configfile) # write back, or write to the new file print ("------------- add ----------") # first determine whether there is if con. has_section ('superman ') = False: con. add_section ('superman ') con ['superman'] = {'SIZE': 'Big '} with open ('example2. ini ', 'w') as configfile: con. write (configfile) # write back, or write to the new file print ("------------- Delete ----------") # con. remove_option ('Europe', 'LIFE') # Delete the con. remove_section ('Europe') # delete a tag with open ('example3. ini ', 'w') as configfile: con. write (configfile) # write back or write to a new file

 

Note: All values must use strings.

 

Hashlib:

Introduction: includes hash encryption functions [hmac and hashlib are common encryption modules in python]

Usage:

# Import module import hashlibmy_md5 = hashlib. md5 () # select the encryption method and create the object my_md5.update (B '000000') # Add the encrypted text my_md5.update ('Chinese '. encode () # convert to bytes to encrypt print (my_md5.hexdigest () # display encrypted information in hexadecimal format (commonly used) ######### sha1 ####### hash = hashlib. sha1 () hash. update (B '123') print (hash. hexdigest () ######### sha256 ######## hash = hashlib. sha256 () hash. update (B '123') print (hash. hexdigest () ######### sha384 ####### hash = hashlib. sha384 () hash. update (B '123') print (hash. hexdigest () ######### sha512 ######## hash = hashlib. sha512 () hash. update (B '123') print (hash. hexdigest ())