run() 方法并不啟動一個新線程，就是在主線程中調(diào)用了一個普通函數(shù)而已。

start() 方法是啟動一個子線程，線程名就是自己定義的name。

因此，如果你想啟動多線程，就必須使用start()方法。

請看實例：（源代碼）

1 使用run()方法啟動線程，它打印的線程名是MainThread，也就是主線程。

import threading,timedef worker():count = 1while True:if count >= 4:breaktime.sleep(1)count += 1print(“thread name = {}”.format(threading.current_thread().name))print(“Start Test run()”)t1 = threading.Thread(target=worker, name=“MyTryThread”)t1.run()print(“run() test end”)

運行結(jié)果：

Start Test run()thread name = MainThreadthread name = MainThreadthread name = MainThreadrun() test end

2 使用start()方法啟動的線程名是我們定義線程對象時設(shè)置的name='MyThread'的值，如果沒有設(shè)置name參數(shù)值，則會打印系統(tǒng)分配的Thread-1,Thread-2…這樣的名稱。

import threading,timedef worker():count = 1while True:if count >= 4:breaktime.sleep(2)count += 1print(“thread name = {}”.format(threading.current_thread().name)) # 當(dāng)前線程名print(“Start Test start()”)t = threading.Thread(target=worker, name=“MyTryThread”)t.start()t.join()print(“start() test end”)

運行結(jié)果:

Start Test start()thread name = MyTryThreadthread name = MyTryThreadthread name = MyTryThreadstart() test end

3 兩個子線程都用run()方法啟動，但卻是先運行t1.run()，運行完之后才按順序運行t2.run()，兩個線程都工作在主線程，沒有啟動新線程，thread ID都是一樣的，因此，run()方法僅僅是普通函數(shù)調(diào)用。

import threading,timedef worker():count = 1while True:if count >= 4:breaktime.sleep(2)count += 1print(“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”)

運行結(jié)果:

Start Test run()thread name = MainThread, thread id = 3920thread name = MainThread, thread id = 3920thread name = MainThread, thread id = 3920thread name = MainThread, thread id = 3920thread name = MainThread, thread id = 3920thread name = MainThread, thread id = 3920run() test end

4 使用start()方法啟動了兩個新的子線程并交替運行，每個子進(jìn)程ID也不同。

import threading,timedef worker():count = 1while True:if count >= 4:breaktime.sleep(2)count += 1print(“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”)

運行結(jié)果:

Start Test start()thread name = MyTryThread1, thread id = 4628thread name = MyTryThread2, thread id = 872thread name = MyTryThread1, thread id = 4628thread name = MyTryThread2, thread id = 872thread name = MyTryThread1, thread id = 4628thread name = MyTryThread2, thread id = 872start() test end

補充知識：python 文件操作常用輪子

path

注意： 對于任何需要處理文件名的問題，都應(yīng)該使用os.path模塊而不是字符串操作。兩個原因，os.path能夠處理移植性問題，如windows,linux。 另一個原因，不要重復(fù)造輪子

獲取文件名

import osfilename = os.path.basename(filepath)print(filename)

獲取文件當(dāng)前文件夾目錄

filename = os.path.dirname(filepath)

同時獲取文件夾和文件名

dirname, filename = os.path.split(filepath)

split 文件擴展名

path_without_ext, ext = os.path.splitext(filepath)# e.g ’hello/world/read.txt’ then# path_without_ext = hello/world/read, ext = .txt

遍歷文件夾下所有文件方法

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

判斷是否為文件 file

os.path.isfile(’/etc/passwd’)

判斷是否為文件夾 folder

os.path.isdir(’/etc/passwd’)

是否是軟鏈接

os.path.islink(’/usr/local/bin/python3’)

軟鏈接真正指向的是

os.path.realpath(’/usr/local/bin/python3’)

size

獲取文件大小

import ossize = os.path.getsize(filepath)print(size)

獲取文件夾大小

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 timet1 = os.path.gettime(’/etc/passwd’)# t1 1272478234.0t2 = time.ctime(t1)# t2 ’Wed Apr 28 12:10:05 2010’

以上這篇Python run()函數(shù)和start()函數(shù)的比較和差別介紹就是小編分享給大家的全部內(nèi)容了，希望能給大家一個參考，也希望大家多多支持好吧啦網(wǎng)。