全方位测试 Python、Java运行速度比较(1)


在正式展开我的观点之前,我想说这只是表达我的个人观点,并非代表科学和权威的论断。我这样做,只是为了给学习编程语言的人们一个参考。

对于初学编程语言的新人而言,如何选择编程语言,首先考虑的问题是哪种语言的运行速度更快。Python 和Java 同是两大面向对象的语言,在这里我对二者的运行速度做了实例演示。

针对不同功能和模块的测试,我分别对Java 和Python 写了功能相同的测试代码,并各自反复测试了三次,取了平均值。结果如下:

Test

Java

Python

Comparison

Standard Output

138.85

30.58

Python 4.5X Faster than Java

Hashtable

17.0

8.22

Python 2X Faster than Java

I/O

56.72

47.36

Python 1.2X Faster than Java

List

5.94

14.32

Java 2.4X Faster than Python

Native Methods

2.475

7.92

Java 3.2X Faster than Python

Interpreter Initialisation

0.25

0.04

Python 6.3X Faster than Java

Object Allocation

23.65

211.11

Java 8X Faster than Python

Interpreter Speed

0.43

2.29

Java 5.3X Faster than Python

时间的单位是秒

再一次,我要说这只是在我的电脑下的大概时间。我的Java (JDK 1.1.7B, blackdown),我的系统(Debian GNU Linux 2.2),我的 (Python 1.5.2) 。

Test-By-Test

ConsoleTest

Python

Java

for x in xrange(1000000):
    print x
    
public class ConsoleTest {
    public static void main(String[] args) {
        for (int i = 0; i < 1000000; i++) {
            System.out.println(i);
        }
    }
}

Hashtest

Python

Java

for i in xrange(1000):

    x={}

    for j in xrange(1000):

        x[j]=i

        x[j]

   

import java.util.Hashtable;

 

public class HashTest {

    public static void main(String[] args) {

        for (int i = 0; i < 1000; i++) {

            Hashtable x = new Hashtable();

            for (int j = 0; j < 1000; j++) {

                x.put(new Integer(i), new Integer(j));

                x.get(new Integer(i));

            }

        }

    }

}

IOTest

Python

Java

f=open('scratch','wb')

for i in xrange(1000000):

    f.write(str(i))

f.close()

   

import java.io.*;

 

public class IOTest

{

    public static void main(String[] args) {

        try {

            File f = new File("scratch");

            PrintWriter ps = new PrintWriter(new OutputStreamWriter

                                             (new FileOutputStream(f)));

            for (int i = 0; i < 1000000; i++) {

                ps.print(String.valueOf(i));

            }

            ps.close();

        }

        catch(IOException ioe) {

            ioe.printStackTrace();

        }

    }

}

ListTest

Python

Java

for i in xrange(1000):

    v=['a','b','c','d','e','f','g']

    for j in xrange(1000):

        v.append(j)

        v[j]

   

import java.util.Vector;

 

public class ListTest {

    public static void main(String[] args) {

        for (int i = 0; i < 1000; i++) {

            Vector v = new Vector();

            v.addElement("a");

            v.addElement("b");

            v.addElement("c");

            v.addElement("d");

            v.addElement("e");

            v.addElement("f");

            v.addElement("g");

            for (int j = 0; j < 1000; j++) {

                v.addElement(new Integer(j));

                v.elementAt(j);

            }

        }

    }

}


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