random shutil shevle xml

时间:2021-10-22 21:46:33

random 模块

import random

print(random.random())#(0,1)----float    大于0且小于1之间的小数

print(random.randint(1,3))  #[1,3]    大于等于1且小于等于3之间的整数

print(random.randrange(1,3)) #[1,3)    大于等于1且小于3之间的整数

print(random.choice([1,'',[4,5]]))#1或者23或者[4,5]

print(random.sample([1,'',[4,5]],2))#列表元素任意2个组合

print(random.uniform(1,3))#大于1小于3的小数,如1.927109612082716 

item=[1,3,5,7,9]
random.shuffle(item) #打乱item的顺序,相当于"洗牌"
print(item)
import random
def make_code(n):
res=''
for i in range(n):
s1=chr(random.randint(65,90))
s2=str(random.randint(0,9))
res+=random.choice([s1,s2])
return res print(make_code(9)) 生成随机验证码

shutil 模块 可以操作全新啊的处理文件模块

# 基于路径的文件复制:
shutil.copyfile('source_file', 'target_file') # 基于流的文件复制:
with open('source_file', 'rb') as r, open('target_file', 'wb') as w:
shutil.copyfileobj(r, w) # 递归删除目标目录
shutil.rmtree('target_folder') # 文件移动
shutil.remove('old_file', 'new_file') # 文件夹压缩
shutil.make_archive('file_name', 'format', 'archive_path') # 文件夹解压
shutil.unpack_archive('unpack_file', 'unpack_name', 'format')

shelve 模块

shelve模块比pickle模块简单,只有一个open函数,返回类似字典的对象,可读可写;key必须为字符串,而值可以是python所支持的数据类型

# 将序列化文件操作dump与load进行封装
s_dic = shelve.open("target_file", writeback=True) # 注:writeback允许序列化的可变类型,可以直接修改值
# 序列化::存
s_dic['key1'] = 'value1'
s_dic['key2'] = 'value2'
# 反序列化:取
print(s_dic['key1'])
# 文件这样的释放
s_dic.close()

import shelve

f=shelve.open(r'sheve.txt')
# f['stu1_info']={'name':'egon','age':18,'hobby':['piao','smoking','drinking']}
# f['stu2_info']={'name':'gangdan','age':53}
# f['school_info']={'website':'http://www.pypy.org','city':'beijing'} print(f['stu1_info']['hobby'])
f.close()

标准输入输出从错误流

import sys
sys.stdout.write('msg')
sys.stderr.write('msg')
msg = sys.stdin.readline() # print默认是对sys.stdout.write('msg') + sys.stdout.write('\n')的封装
# 格式化结束符print:print('msg', end='')

xml xml文件操作模块

import xml.etree.ElementTree as ET
# 读文件
tree = ET.parse("xmltest.xml")
# 根节点
root_ele = tree.getroot()
# 遍历下一级
for ele in root_ele:
print(ele) # 全文搜索指定名的子标签
ele.iter("标签名")
# 非全文查找满足条件的第一个子标签
ele.find("标签名")
# 非全文查找满足条件的所有子标签
ele.findall("标签名") # 标签名
ele.tag
# 标签内容
ele.text
# 标签属性
ele.attrib # 修改
ele.tag = "新标签名"
ele.text = "新文本"
ele.set("属性名", "新属性值") # 删除
sup_ele.remove(sub_ele) # 添加
my_ele=ET.Element('myEle')
my_ele.text = 'new_ele'
my_ele.attrib = {'name': 'my_ele'}
root.append(my_ele) # 重新写入硬盘
tree.write("xmltest.xml")

xml的格式如下,就是通过<>节点来区别数据结构的:

<?xml version="1.0"?>
<data>
<country name="Liechtenstein">
<rank updated="yes">2</rank>
<year>2008</year>
<gdppc>141100</gdppc>
<neighbor name="Austria" direction="E"/>
<neighbor name="Switzerland" direction="W"/>
</country>
<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> xml数据

xml协议在各个语言里的都 是支持的,在python中可以用以下模块操作xml:

# print(root.iter('year')) #全文搜索
# print(root.find('country')) #在root的子节点找,只找一个
# print(root.findall('country')) #在root的子节点找,找所有
import xml.etree.ElementTree as ET

tree = ET.parse("xmltest.xml")
root = tree.getroot()
print(root.tag) #遍历xml文档
for child in root:
print('========>',child.tag,child.attrib,child.attrib['name'])
for i in child:
print(i.tag,i.attrib,i.text) #只遍历year 节点
for node in root.iter('year'):
print(node.tag,node.text)
#--------------------------------------- import xml.etree.ElementTree as ET tree = ET.parse("xmltest.xml")
root = tree.getroot() #修改
for node in root.iter('year'):
new_year=int(node.text)+1
node.text=str(new_year)
node.set('updated','yes')
node.set('version','1.0')
tree.write('test.xml') #删除node
for country in root.findall('country'):
rank = int(country.find('rank').text)
if rank > 50:
root.remove(country) tree.write('output.xml')
#在country内添加(append)节点year2
import xml.etree.ElementTree as ET
tree = ET.parse("a.xml")
root=tree.getroot()
for country in root.findall('country'):
for year in country.findall('year'):
if int(year.text) > 2000:
year2=ET.Element('year2')
year2.text='新年'
year2.attrib={'update':'yes'}
country.append(year2) #往country节点下添加子节点 tree.write('a.xml.swap')

自己创建xml文档:

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")
sex.text = ''
name2 = ET.SubElement(new_xml,"name",attrib={"enrolled":"no"})
age = ET.SubElement(name2,"age")
age.text = '' et = ET.ElementTree(new_xml) #生成文档对象
et.write("test.xml", encoding="utf-8",xml_declaration=True) ET.dump(new_xml) #打印生成的格式