1.Python Profile
What is 1.1 Python
I believe many of my friends were removed from the IT sector all know, Python is a hot spot in recent years, most of the fire, no one. From the terms of its nature and we know C, java, php and so there is nothing essentially different, but also a development language, and has advanced to the mainstream than 20 kinds of development language of top 5 (the latest data from TIOBE charts).
1.2 Python origin and development trends
Past originator from Python "turtle t." In 1989, Guido van Rossum (Guido van Rossum) in Amsterdam in order to fill the empty Christmas, determined to develop a new script interpreter, since Python and the founder of "turtle t" entered the public view. He hoped that this new language called Python, able to meet his ideal: to create a C shell and between, full-featured, easy to use, scalable language.
In 1991, the first born Python compiler. It is based on the C language, and be able to call the C language library. After later versions of constantly updating innovation, Python reached a very node landmark, namely version 2.4 of the 2004 birth of the most popular WEB framework Django! After six years of development to Python 2.7 version, which is the newest version 2.x and far more widely used version.
Unlike the previous 2.7 version 2.x version of the birth of vertical replacement logic, it is a transition bridge between versions 2.x and 3.x versions in order to inherit the new features of version 3.x maximum extent possible, at the same time try to keep compatibility with the 2.x.
Therefore 3.x versions prior to version 2.7 has been around, from version 3.0 began in 2008, python3.x system was the rapid development trend, active version of the update, it has been developed to the latest 3.5.2 version. Version 3.5 is the current version 3.x series in the mainstream and widely used, demo follow-up procedures, and default are based on the 3.5 version launched.
1.3 Python 2 VS Python 3
Many beginners will start python entangled in the way of learning from version 2.x or 3.x version. A brief comparison of individual learning differences at both learned here:
Version 3.x PRINT IS A FUNCTION, more simple and convenient to use;
3.x versions default unicode will be used, my mother no longer have to worry about your program coding problem;
3.x versions of some libraries have been renamed, as well as specific follow-up study to stay in the expanded in-depth;
The current 3.x version also does not fully support Twisted module, which is probably the biggest regret 3.x version. Do not be too tangled this point, officials are said to make up for this deficiency, but also believe that we can have a solution :)
In summary:. After Python 2.x is legacy, Python 3.x is the present and future of the language waves pushed before the waves, python future belongs 3.x series, officially announced in 2020 no longer supports 2.x the most nb series version 2.7, 2.x version will gradually come to an end eventually be inscribed in the development of language monument.
So learning 3.x version of Yes!
1.4 Python's strengths and weaknesses
Two dozen mainstream development language, python why that is so rapid trend sweeping the seven continents in eight ocean it 20 years? These are excellent features its own decision.
Python advantages:
1. "elegant", "clear", "simple"
This is positioning the python, python makes the program look easy to understand, easy for beginners to get started, learn at a lower cost. But with the only in-depth study, python as competent to meet the development needs of complex scenes. Quoted a statement, Python's philosophy is simple and elegant, try to write code that is easy to understand, try to write less code.
2. Development of high efficiency
python as a high-level language, has a wealth of third-party libraries, official library also has a corresponding function module support, covering a lot of the content network, file, GUI, database, text, and so on. So developers do not need hands-on, you can directly call the face of mainstream functional requirements, on the basis of their fists on the basis of the library, you can save a lot of skill and time costs, significantly reduce development cycle.
3. No attention to underlying details
As a high-level Python development language, when programming without paying attention to the underlying details (such as memory management, etc.).
4. Powerful
Python is a comprehensive front-end back-end-take-all language, powerful, php qualified for the role it can do, as to how the back-end competent, need to comprehend gradually in subsequent studies.
5. Portability
Python can run on a variety of mainstream platform for the development of the program as long as the bypass, you can run the dependency system platform under the premise without modification on a variety of platforms, specific follow-up study to be well under way. Other advantages is yet to be discovered.
A coin always has two sides, so Python has weaknesses? The answer is yes, are summarized as follows:
Python Cons:
1. The code runs slower
Because Python is a high-level development language, unlike c languages can dig squeeze the maximum performance of the hardware underlying hardware extent, so its speed is much slower than the c language. Another reason is, Python is an interpreted language, your code will be executed when translated into machine code line by line CPU can understand, this translation process is very time consuming, so it is slow. The C program is compiled directly into machine code that can be executed before running the CPU, it is very fast.
But it notes that this does not need to slow the pursuit of high-performance applications in terms of the hardware is not a problem, because they are more the order of magnitude is not a user can intuitively feel! Think of the time required for program execution order of magnitude? For example, the development of a downloaded MP3 web applications, runtime C program needs 0.001 seconds, and run-time Python program needs 0.1 seconds, slower than 100 times, but the network more slowly, need to wait one second, almost no difference in user experience unless you use very precise timer to time.
2. Must open source publishing program
what? Is there a mistake? Yes, we must be open-source publishing program! Or because Python is an interpreted language, there is no process of compiling the package (the latest python is said to be packed, but the essence is still the source code and the interpreter to play together without much practical significance). Think of our shell script is not also the case, you can publish a black box procedure without publishing the source code to let others use it properly?
The only drawback when you want simply by selling software developed products to make money. But in this age of the Internet's development, not to make money by selling the product itself more and more mainstream business model, so the problem is not impossible to solve.
To sum up, the advantages outweighed the disadvantages Python, but the disadvantage is not a fundamental issue in the case of qualified majority it, fundamental, enjoy the fun and convenience it has brought us now!
1.5 Python's field of application
Python A typical field of application as follows:
1. Cloud computing development
The language of the hottest areas of cloud computing, a typical representative openstack.
2. web development
Many outstanding web framework, a large number of excellent web sites (Youtube, instagrm, watercress, etc.) are based on python development.
3. System operation and maintenance
Development of various automated tools, CMDB, monitoring alarm systems, fortress machine, batch configuration management & distribution tools, etc. can get. This is an area they need to focus on learning.
4. scientific computing, AI
It is understood that for Google Go online war A fat dog on the use of python development (it is estimated that only part of it).
5. GUI graphics processing
Temporarily do not have much experience, follow comprehend it.
6. Web crawler
I do not know whether to classify a separate web crawler appropriate, tentatively so be it. Web crawlers everywhere these days, many of which are based on python development, including Google's crawlers. This estimate is an indispensable tool reptile engineer it.
What place in Python 1.6
Several well-known companies to fresh application case, to show respect:
Google: Google app engine, google earth, reptiles, advertising
Youtube: the world's largest online video site based on python development, good strong
Instagram: America's largest photo-sharing sites, all based on python development
facebook: a lot of basic libraries python-based development
Redhat: yum package management tool based on python development
Well-known Internet company's application: watercress, know almost website, there are many major Internet companies (Ali, Tencent, Baidu, Jinshan, Sohu, Shanda, Netease, Sina, Netease, husk, potatoes, etc.) is done by python variety of tasks
two. Python Installation
3.7.0-Python (32/64 ) Bit Download:
pan.baidu.com/s/1Ub89cbTjDm3GJg4ce2NKdQ
Extraction code: w614
After the class was a big brother Amway, found a very useful public number, which has detailed method to download almost all software, name software installation housekeeper, may recommend you look at this download method is what I carry over, everyone Download the median time to pay attention to your own computer, not on the wrong
- Select [python-3.7.0] archive, right-click to select [extract to python-3.7.0].
2. Double-click to open the [python-3.7.0] folder.
3. Right-click My Computer on the desktop mouse and select Properties to view their computer-digit, 64-bit system, select [python-3.7.0.amd64] (32-bit system is selected above) and then right-click to select [Administrator run].
4. Select [Add Python 3.7 to PATH], then click [Customize installation].
5. Click [Next].
6. Click [Browse] to change the installation directory software, it is recommended in the D drive or other disk Python37] [create a new folder, click [Install].
7. installation.
8. When the installation is complete, click [Close].
9. Find and open [IDLE (Python 3.7 64-bit)] in the Start menu bar.
10. The installation is completed.
The first to write blog ah, no experience, blind himself wondering if you've seen here, you must be a very thoughtful person, if you can, I want to give praise,, relationship to the point of a performance assessment we usually drop ,Thank you