官术网_书友最值得收藏!

Python versions

At the time of writing this book in early 2017, Python is going through a transition period of moving from Python version 2 to Python version 3. Unfortunately Python 3 is not backward compatible with Python 2. When I say transition, keep in mind that Python 3 was released back in 2008, over nine years ago with active development with the most recent release of 3.6. The latest Python 2.x release, 2.7, was released over six years ago in mid 2010. Fortunately, both version can coexist on the same machine. Personally, I use Python 2 as my default interpreter when I type in Python at the Command Prompt, and I use Python 3 when I need to use Python 3. More information is given in the next section about invoking Python interpreter, but here is an example of invoking Python 2 and Python 3 on the Ubuntu Linux machine:

    echou@pythonicNeteng:~$ python
Python 2.7.12 (default, Nov 19 2016, 06:48:10)
[GCC 5.4.0 20160609] on linux2
Type "help", "copyright", "credits" or "license" for
more information.
>>> exit()
    echou@pythonicNeteng:~$ python3
Python 3.5.2 (default, Nov 17 2016, 17:05:23)
[GCC 5.4.0 20160609] on linux
Type "help", "copyright", "credits" or "license" for
more information.
>>> exit()

With the 2.7 release being end of life on extended support only for security updates, most Python frameworks are now supporting Python 3. Python 3 also has lots of good features such as asynchronous I/O that can be taken advantage of when we need to optimize our code. This book will use Python 3 for its code examples.

If the particular library or the framework does not support Python 3, such as Ansible (they are actively working on porting to Python 3), it will be pointed out, so you can use Python 2 instead.

主站蜘蛛池模板: 仁化县| 剑河县| 乌兰浩特市| 新化县| 镇江市| 六枝特区| 太康县| 雅江县| 泰顺县| 沾益县| 托里县| 台前县| 图木舒克市| 长宁区| 钦州市| 宣化县| 确山县| 平果县| 广灵县| 寿光市| 信丰县| 临清市| 会理县| 石河子市| 乌恰县| 平乡县| 湖口县| 龙门县| 兰溪市| 洛阳市| 文登市| 天门市| 自治县| 昌图县| 辉南县| 黎城县| 西林县| 乌兰浩特市| 大方县| 东乡县| 渑池县|