day22-python之模块

1.os

import os

# print(os.getcwd())
# os.chdir("..")
# print(os.getcwd())

# os.makedirs('dirname1/dirname2')
# os.removedirs("dirname1/dirname2")
# print(os.listdir())
# print(os.stat("test.py"))

# print(os.system("dir"))
#
# print(os.path.split(r"C:UsersAdministrator脱产三期day22sss.py"))
# print(os.path.dirname(r"C:UsersAdministrator脱产三期day22sss.py"))
# print(os.path.basename(r"C:UsersAdministrator脱产三期day22sss.py"))
a="C:UsersAdministrator"
b="脱产三期day22sss.py"
#
os.path.join(a,b)#  路径拼接

2.xml解析

# import xml.etree.ElementTree as ET



# tree = ET.parse("../day22/xml_lesson.xml")
# root = tree.getroot()
# print(root.tag)


# for i in root:
#
#     # print(i.tag)
#     # print(i.attrib)
#     for j in i:
#         # print(j.tag)
#         # print(j.attrib)
#         print(j.text)




# # 遍历xml文档
# for child in root:
#     # print(child.tag, child.attrib)
#     for i in child:
#         print(i.tag, 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("../day22/xml_lesson.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", "no")
# #
# tree.write("../day22/xml_lesson.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')


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 = '33'
name2 = ET.SubElement(new_xml, "name", attrib={"enrolled": "no"})
age = ET.SubElement(name2, "age")
age.text = '19'



et = ET.ElementTree(new_xml)  # 生成文档对象
et.write("test1.xml", encoding="utf-8", xml_declaration=True)

ET.dump(new_xml)  # 打印生成的格式

3.json & pickle

# dic='{"name":"alex"}'
# f=open("hello","w")
# f.write(dic)
#
# f_read=open("hello","r")
# data=f_read.read()
# print(type(data))
# data=eval(data)
# print(data["name"])

import json


# dic={'name':'alex'}#---->{"name":"alex"}----->'{"name":"alex"}'
# i=8                 #---->'8'
# s='hello'          #---->"hello"------>'"hello"'
# l=[11,22]           #---->"[11,22]"
# #
# f=open("new_hello","w")
#
# dic_str=json.dumps(dic)
# f.write(dic_str)    #json.dump(dic,f)



# f_read=open("new_hello","r")
# data=json.loads(f_read.read())      # data=json.load(f)
#
# #
# print(data["name"])
# print(data)
# print(type(data))

# print(s)
# print(type(s))


# data=json.dumps(dic)

# print(data)     #{"name": "alex"}
# print(type(data))


#注意：
# import json
#
# with open("hello","r") as f:
#     data=f.read()
#     data=json.loads(data)
#     print(data["name"])

#----------------------pickle-------
# import pickle

# dic = {'name': 'alvin', 'age': 23, 'sex': 'male'}

# print(type(dic))  # <class 'dict'>
#
# j = pickle.dumps(dic)
# print(type(j))  # <class 'bytes'>
#
# f = open('../day22/序列化对象_pickle', 'wb')  # 注意是w是写入str,wb是写入bytes,j是'bytes'
# f.write(j)  # -------------------等价于pickle.dump(dic,f)
#
# f.close()
# # -------------------------反序列化
# import pickle
#
# f = open('../day22/序列化对象_pickle', 'rb')
# #
# data = pickle.loads(f.read())  # 等价于data=pickle.load(f)
#
# print(data['age'])
# # -------------------------shelve模块---------
import shelve
#
f = shelve.open(r'shelve1.bak')  # 目的：将一个字典放入文本 f={}
#
f['stu1_info']={'name':'alex','age':'18'}
f['stu2_info']={'name':'alvin','age':'20'}
f['school_info']={'website':'oldboyedu.com','city':'beijing'}
f.close()

print(f.get('stu1_info')['age'])



# dic={}
#
# dic["name"]="alvin"
# dic["info"]={"name":"alex"}

4.eval

print(eval("12+(34*6+2-5*(2-1))"))

5.sys

import sys
# # print(sys.argv)
#
# command=sys.argv[1]
# path=sys.argv[2]
#
# if command=="post":
#     pass
#
# elif command=="get":
#     pass
#
import time
for i in range(100):
    sys.stdout.write("#")
    time.sleep(0.1)
    sys.stdout.flush()