run() 方法并不启动一个新线程，就是在主线程中调用了一个普通函数而已。
start() 方法是启动一个子线程，线程名就是自己定义的name。
因此，如果你想启动多线程，就必须使用start()方法。
请看实例：（源代码）
1 使用run()方法启动线程，它打印的线程名是mainthread，也就是主线程。
import threading,time
def worker():
count = 1
while true:
if count >= 4:
break
time.sleep(1)
count = 1
print(“thread name = {}”.format(threading.current_thread().name))
print(“start test run()”)
t1 = threading.thread(target=worker, name=“mytrythread”)
t1.run()
print(“run() test end”)
运行结果：
start test run() thread name = mainthread thread name = mainthread thread name = mainthread run() test end
2 使用start()方法启动的线程名是我们定义线程对象时设置的name="mythread"的值，如果没有设置name参数值，则会打印系统分配的thread-1,thread-2…这样的名称。
import threading,time
def worker():
count = 1
while true:
if count >= 4:
break
time.sleep(2)
count = 1
print(“thread name = {}”.format(threading.current_thread().name)) # 当前线程名
print(“start test start()”)
t = threading.thread(target=worker, name=“mytrythread”)
t.start()
t.join()
print(“start() test end”)
运行结果:
start test start() thread name = mytrythread thread name = mytrythread thread name = mytrythread start() test end
3 两个子线程都用run()方法启动，但却是先运行t1.run()，运行完之后才按顺序运行t2.run()，两个线程都工作在主线程，没有启动新线程，thread id都是一样的，因此，run()方法仅仅是普通函数调用。
import threading,time
def worker():
count = 1
while true:
if count >= 4:
break
time.sleep(2)
count = 1
print(“thread name = {}, thread id = {}”.format(threading.current_thread().name,
threading.current_thread().ident))
print(“start test run()”)
t1 = threading.thread(target=worker, name=“t1”)
t2 = threading.thread(target=worker, name=‘t2')
t1.run()
t2.run()
print(“run() test end”)
运行结果:
start test run() thread name = mainthread, thread id = 3920 thread name = mainthread, thread id = 3920 thread name = mainthread, thread id = 3920 thread name = mainthread, thread id = 3920 thread name = mainthread, thread id = 3920 thread name = mainthread, thread id = 3920 run() test end
4 使用start()方法启动了两个新的子线程并交替运行，每个子进程id也不同。
import threading,time
def worker():
count = 1
while true:
if count >= 4:
break
time.sleep(2)
count = 1
print(“thread name = {}, thread id = {}”.format(threading.current_thread().name,
threading.current_thread().ident))
print(“start test start()”)
t1 = threading.thread(target=worker, name=“mytrythread1”)
t2 = threading.thread(target=worker, name=“mytrythread2”)
t1.start()
t2.start()
t1.join()
t2.join()
print(“start() test end”)
运行结果:
start test start() thread name = mytrythread1, thread id = 4628 thread name = mytrythread2, thread id = 872 thread name = mytrythread1, thread id = 4628 thread name = mytrythread2, thread id = 872 thread name = mytrythread1, thread id = 4628 thread name = mytrythread2, thread id = 872 start() test end
补充知识：python 文件操作常用轮子
path
注意： 对于任何需要处理文件名的问题，都应该使用os.path模块而不是字符串操作。两个原因，os.path能够处理移植性问题，如windows,linux。 另一个原因，不要重复造轮子
获取文件名
import os filename = os.path.basename(filepath) print(filename)
获取文件当前文件夹目录
filename = os.path.dirname(filepath)
同时获取文件夹和文件名
dirname, filename = os.path.split(filepath)
split 文件扩展名
path_without_ext, ext = os.path.splitext(filepath) # e.g 'hello/world/read.txt' then # path_without_ext = hello/world/read, ext = .txt
遍历文件夹下所有文件方法
import glob
pyfiles = glob.glob('*.py')
or
def getallfiles(filepath, filelist=[]):
for root, dirs, files in os.walk(filepath):
for f in files:
filelist.append(os.path.join(root, f))
print(f)
return filelist
判断是否为文件 file
os.path.isfile('/etc/passwd')
判断是否为文件夹 folder
os.path.isdir('/etc/passwd')
是否是软链接
os.path.islink('/usr/local/bin/python3')
软链接真正指向的是
os.path.realpath('/usr/local/bin/python3')
size
获取文件大小
import os size = os.path.getsize(filepath) print(size)
获取文件夹大小
import os
def getfilesize(filepath, size=0):
for root, dirs, files in os.walk(filepath):
for f in files:
size = os.path.getsize(os.path.join(root, f))
print(f)
return size
print(getfilesize(".")）
time
import time
t1 = os.path.gettime('/etc/passwd')
# t1 1272478234.0
t2 = time.ctime(t1)
# t2 'wed apr 28 12:10:05 2010'
