f = open('test.txt', 'w+')
f.write('World') 
print('1.创建test.txt文件，World写入文件') 

f = open('test.txt', 'r+')
f.write('Hello')
print('2.打开test.txt文件，Hello覆盖文件内容')

f = open('tset.txt','a')
f.write(' ')
print(r'3.打开test.txt文件，在文件尾部追加空格" "')

fname = 'C:/Users/Lenovo/Desktop/py/test.txt'
f = open(fname, 'a+')
f.write('World')
print('4.打开test.txt文件，在文件尾部追加World')

f_name ='test.txt'
f = None
try:
    f = open(f_name)
    print('打开文件成功')
    content = f.read()
    print(content)
except FileNotFoundError as e:
    print('文件不存在，请先使用ch12_1.py程序创建文件')
except OSError as e:
    print('处理OSError异常')
finally:	 	
 	if f is not None:	 	
 	    f.close()	
 	    print('关闭文件成功')	
      
f_name = 'test.txt'
with open(f_name) as f:
    content = f.read()
    print(content)


f_name = 'src_file.txt'

with open(f_name, 'r', encoding='gbk') as f:
    lines = f.readlines()
    copy_f_name = 'dest_file.txt'
    with open(copy_f_name, 'w', encoding='utf-8') as copy_f:
        copy_f.writelines(lines)
        print('文件复制成功')


f_name = 'logo.png'

with open(f_name, 'rb') as f:
    b = f.read()
    copy_f_name = 'logo2.png'
    with open(copy_f_name, 'wb') as copy_f:
        copy_f.write(b)
        print('文件复制成功')
        
        
import threading

t = threading.current_thread

print(t.name)
print(threading.active_count())
t = threading.main_thread()        
print(t.name)

import time

def thread_body():
    t = threading.current_thread()
    for n in range(5):
        print('第{0}次执行线程{1}'.format(n,t.name))
        time.sleep(2)
    print('线程{0}执行完成！'.format(t.name))
    
class SmallThread(threading.Thread):
    def __int__(self, name=None):
        super().__init__(name=name)
    def run(self):
        t = threading.current_thread()
        for n in range(5):
            print('第{0}次执行线程{1}'.format(n, t.name))
            time.sleep(2)
        print('线程{0}执行完成！'.format(t.name))
t1 = SmallThread()
t2 = SmallThread(name='Mythread')
t1.start()
t2.start()

value = []
def thread_body():
    print('t1子线程开始...')
    for n in range(2):
        print('t1子线程执行...')
        value.append(n)
        time.sleeap(2)
    print('t1子线程结束。') 
print('主线程开始执行...')
t1 = threading.Thread(target=thread_body)
t1.start()
t1.join()
print('value = {0}'.format(value))
print('主线程继续执行...')


import threading
import time

isrunning = True
def workthread_body():
    while isrunning: 	
        print('工作线程执行中...')
        time.sleep(5)
    print('工作线程结束。')
def	controlthread_body():
    global isrunning
    while isrunning: 	

        command = input('请输入停止指令：')
        if command == 'exit':	
 	        isrunning = False
            print('控制线程结束。')	
workthread = threading.Thread(target=workthread_body)	
 	 	
workthread.start()	
controlthread = threading.Thread(target=controlthread_body)
controlthread.start()


import threading
import time
import urllib.request
isrunning = True
def workthread_body():
    while isrunning:
        print('工作线程执行下载任务...')
        download()
        time.sleep(5)
    print('工作线程结束。')
def controlthread_body():
    global isrunning
    while isrunning:
        command = input('请输入停止指令:')
        if command == 'exit':
            isrunning= False
            print('控制线程结束。')	

def download():
    url = 'http://localhost:8080/NoteWebService/logo.png'	
    reg = urllib.request.Request(url)
    with urllib.request.urlopen(url) as response:
        data = response.read()
        f_name = 'download.png'
        with open(f_name, 'wb') as f:
            f.write(data)
            print('下载文件成功')
workthread = threading.Thread(target=workthread_body) 
workthread.start()
controlthread = threading.Thread(target=controlthread_body)
controlthread.start()