----------------------------接 python內置模塊（二）---------------------------
八、 shelve模塊
shelve模塊是一個簡單的k,v將內存數據通過文件持久化的模塊，可以持久化任何pickle可支持的python數據格式，他只有一個函數就是open()，這個函數接收一個參數就是文件名，然後返回一個shelf
對象，你可以用他來存儲東西，就可以簡單的把他當作一個字典，當你存儲完畢的時候，就調用close
函數來關閉。
>>> import shelve
>>> sfile = shelve.open('shelve_test') # 打開一個文件
>>> sfile['k1'] = [] # 持久化存儲列表
>>> sfile['k1']
[]
>>> sfile.close() # 文件關閉
九、 xml處理模塊
xml是實現不同語言或程序之間進行數據交換的協議，xml通過<>節點來區別數據結構的:
<?xml version="1.0"?>
<data> <country name="Singapore"> <rank updated="yes">5</rank> <year>2011</year> <gdppc>59900</gdppc> <neighbor name="Malaysia" direction="N"/> </country> <country name="Panama"> <rank updated="yes">69</rank> <year>2011</year> <gdppc>13600</gdppc> <neighbor name="Costa Rica" direction="W"/> <neighbor name="Colombia" direction="E"/> </country></data>遍歷xml文檔
import xml.etree.ElementTree as ET
tree = ET.parse("test.xml")
root = tree.getroot()
print(root.tag)
#遍歷xml文檔
for child in root:
print(child.tag, child.attrib)
for i in child:
print(i.tag,i.text)
#只遍歷year 節點
for node in root.iter('year'):
print(node.tag,node.text)
修改xml文檔
import xml.etree.ElementTree as ET
tree = ET.parse("test.xml")
for node in root.iter('year'):
new_year = int(node.text) + 1
node.text = str(new_year)
node.set("updated","yes")
tree.write("test.xml")
for node in root.iter('year'):
print(node.tag,node.text)
刪除xml內容
#刪除node
import xml.etree.ElementTree as ET
tree = ET.parse("test.xml")
for country in root.findall('country'):
rank = int(country.find('rank').text)
if rank > 50:
root.remove(country)
tree.write('test.xml')
for child in root:
print(child.tag, child.attrib)
for i in child:
print(i.tag,i.text)
創建xml文檔
import xml.etree.ElementTree as ET
new_xml = ET.Element("namelist")
name = ET.SubElement(new_xml,"name",attrib={"enrolled":"yes"})
age = ET.SubElement(name,"age",attrib={"checked":"no"})
sex = ET.SubElement(name,"sex")
age.text = '33'
sex.text = 'F'
name2 = ET.SubElement(new_xml,"name",attrib={"enrolled":"no"})
age = ET.SubElement(name2,"age")
sex = ET.SubElement(name2,"sex")
age.text = '19'
sex.text = 'M'
et = ET.ElementTree(new_xml) #生成文檔對象
et.write("test.xml", encoding="utf-8",xml_declaration=True)
ET.dump(new_xml) #打印生成的格式
<namelist> <name enrolled="yes"> <age checked="no">33</age> <sex>F</sex> </name> <name enrolled="no"> <age>19</age> <sex>M</sex> </name> </namelist>
十、 ConfigParser模塊
用於生成和修改常見配置文檔，當前模塊的名稱在 python 3.x 版本中變更爲 configparser。
常見軟件配置文檔格式如下：
[DEFAULT]
ServerAliveInterval = 45Compression = yesCompressionLevel = 9ForwardX11 = yes[bitbucket.org]User = hg[topsecret.server.com]Port = 50022ForwardX11 = no生成配置文件方法：
import configparser
config = configparser.ConfigParser()
config["DEFAULT"] = {}
config["DEFAULT"]['ServerAliveInterval']= '45'
config["DEFAULT"]['Compression'] = 'yes'
config["DEFAULT"]['CompressionLevel'] = '9'
config['DEFAULT']['ForwardX11'] = 'yes'
config['bitbucket.org'] = {}
config['bitbucket.org']['User'] = 'hg'
config['topsecret.server.com'] = {}
config['topsecret.server.com']['Host Port'] = '50022'
config['topsecret.server.com']['ForwardX11'] = 'no'
with open('example.ini', 'w') as configfile:
config.write(configfile)
從配置文件中讀出內容：
import configparser
config = configparser.ConfigParser()
print(config.sections())
print(config.read('example.ini')) //想要讀取配置文件中內容需要先執行此操作將內容讀進內存；
print(config.sections())
print(config['bitbucket.org']['User'])
for key in config['DEFAULT']:
print(key)
結果是：
[]
['example.ini']
['bitbucket.org', 'topsecret.server.com']
hg
serveraliveinterval
compression
compressionlevel
forwardx11
configparser增刪改查語法
import configparser
config = configparser.ConfigParser()
config.read('example.ini')
# ********* 讀 *********
#secs = config.sections()
#print(secs)
#options = config.options('bitbucket.org') // 獲取sections下所有key值
#print(options)
#item_list = config.items('bitbucket.org') // 獲取sections下所有items
#print(item_list)
#val = config.get('bitbucket.org','user') // 在sections 下找到某key值
#val = config.getint('bitbucket.org','compressionlevel') // 先get 後int，即將int類型的
字符串轉換成int類型
#print(val)
# ********** 改寫 ***********
#sec = config.remove_section('bitbucket.org')
#config.write(open('new_example.ini', "w"))
#secs = config.has_section('bitbucket')
#config.add_section('bitbucket')
#config.write(open('example.cfg', "w"))
#config.set('bitbucket.org','user','shuoming')
#config.write(open('new_example.cfg', "w"))
#config.remove_option('bitbucket.org','user')
#config.write(open('new_example.cfg', "w"))
----------------------------接 內置模塊(四)---------------------------