同时遍历两个或更多的序列,可以使用zip()组合: questions = ['name', 'quest', 'favorite color'] answers = ['lancelot', 'the holy grail', 'blue'] for q, a in zip(questions, answers): print('What is your {0}? It is {1}.'.format(q, a)) 要反向遍历一个序列,首先指定这个序列,然后...
四、文件中的内容定位f.read() 读取之后,文件指针到达文件的末尾,如果再来一次f.read()将会发现读取的是空内容,如果想再次读取全部内容,必须将定位指针移动到文件开始: f.seek(0) 这个函数的格式如下(单位是bytes): f.seek(offset, from_what) from_what表示开始读取的位置,offset表示从from_what再移动一定量...
print(str.rpartition("name"))#反向找到第一个name,分割为三部分 str = """my name is qlee what is your name""" print(str.splitlines()) 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 输出: ['my', 'name', 'is', 'qlee,', 'what', 'is', 'your', 'name'] ['my name ', 's qle...
Here's a fun project attempting to explain what exactly is happening under the hood for some counter-intuitive snippets and lesser-known features in Python.While some of the examples you see below may not be WTFs in the truest sense, but they'll reveal some of the interesting parts of ...
http://stackoverflow.com/questions/136097/what-is-the-difference-between-staticmethod-and-classmethod-in-python https://realpython.com/blog/python/instance-class-and-static-methods-demystified/ 4 类变量和实例变量 类变量: 是可在类的所有实例之间共享的值(也就是说,它们不是单独分配给每个实例的)...
fd=nltk.FreqDist(tags) fd.tabulate() 1. 2. 3. 4. 结果如下: VBN VB VBD JJ IN QL , CS RB AP VBG RP VBZ QLP BEN WRB . TO HV 15 10 8 5 4 3 3 3 3 1 1 1 1 1 1 1 1 1 1 1. 2. 同样的,如果我们想的到三连词, 可以采用trigrams的方法。
This is perhaps the essence of why we choose to use Python day after day. This philosophy resonates within us as what we want and expect from a language. And if this resonates with you, then Python is probably a good choice for you as well. Motivation If you justpicked up this book...
(directly or indirectly) from BaseException. This is the root of the exception hierarchy. This is not new as a recommendation, but the requirement to inherit from BaseException is new. (Python 2.6 still allowed classic classes to be raised, and placed no restriction on what you can catch.)...
What's the turtle library? turtle是一个预安装的Python库,它允许用户通过提供的虚拟画布来创建图片和形状。其中,用于屏幕上绘图的笔叫做海龟笔,这便是该库名称的由来。简而言之,Python海龟库可以帮助新程序员以一种有趣和交互式的方式感受用Python编程是什么样子的。
E. An execption is thrown 1 2 3 4 1. kvps = {"1":1,"2":2} 2. theCopy = kvps 3. kvps["1"] = 5 4. sum = kvps["1"] + theCopy ["1"] 5. print sum ---10 103. what gets printde() ? B 1. numbers = [1,2,3,4] ...