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with statement Here is the syntax of the with statement: with expression as var: statements The expression should be a context manager object, or it s
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posted @ 2024-07-31 21:50
ZhangZhihuiAAA
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Figure 20.4: Built-in exceptions The class BaseException is the base class of all the built-in exception classes. From BaseException, four classes nam
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posted @ 2024-07-31 21:03
ZhangZhihuiAAA
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There are two approaches that can be followed when we want to deal with exceptions that occur due to unusual events: LBYL - Look Before You Leap EAFP
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posted @ 2024-07-31 20:48
ZhangZhihuiAAA
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>>> list(map(lambda x, y: x * y, [1,2,3,4], [5,6,7,8])) [5, 12, 21, 32] Here we have called the map function and sent a lambda expression as first arg
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posted @ 2024-07-31 20:13
ZhangZhihuiAAA
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Functional programming is a programming paradigm in which most of the work in a program is done using pure functions. A pure function is a function wi
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posted @ 2024-07-31 17:23
ZhangZhihuiAAA
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We can place lambda function inside list and dictionary literals. This way we can use lambda expressions to create jump tables. >>> L = [lambda s: s.s
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posted @ 2024-07-31 17:11
ZhangZhihuiAAA
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A closure is a nested function that can access free variables from an enclosing function even after it has finished its execution. We know that, like
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posted @ 2024-07-31 17:08
ZhangZhihuiAAA
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We have used functions to decorate functions and to decorate classes. Now, we will see how to define a class as a decorator. At the start of this chap
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posted @ 2024-07-31 16:24
ZhangZhihuiAAA
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When we talk about decorating classes, we can either decorate individual methods or we can create a decorator to decorate the whole class. class MyCla
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posted @ 2024-07-31 15:28
ZhangZhihuiAAA
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A decorator is a callable that takes a callable as input and returns a callable. This is the general definition of a decorator. The callable in this d
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posted @ 2024-07-31 15:19
ZhangZhihuiAAA
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The task of implementing iterators can be simplified by using generators. We have seen how to create custom iterators using the object-oriented way, i
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posted @ 2024-07-31 11:20
ZhangZhihuiAAA
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The itertools module contains special functions to create iterators for efficient looping. It has three broad categories of iterators - infinite itera
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posted @ 2024-07-31 10:40
ZhangZhihuiAAA
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If we want objects of this class to be used in iteration contexts, then they should support the iteration protocol. To make this class iterable, we ca
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posted @ 2024-07-31 10:33
ZhangZhihuiAAA
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In our first example, we will create iterable objects, which, when iterated over, will give out cubes of numbers, and these objects will support multi
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posted @ 2024-07-31 10:29
ZhangZhihuiAAA
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There are many built-in functions and methods that return iterables and iterators. Here are a few examples: range() returns an iterable dict.keys() re
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posted @ 2024-07-31 09:43
ZhangZhihuiAAA
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class Engine: def __init__(self,power): self.power = power def start(self): self.draw_current() self.spin() self.ignite() def draw_current(self): prin
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posted @ 2024-07-31 09:34
ZhangZhihuiAAA
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We have seen that if we have to define a group of classes that have similar features and show common behavior, we can define a base class and then inh
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posted @ 2024-07-31 09:30
ZhangZhihuiAAA
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The three main features of object-oriented programming are - encapsulation, inheritance and polymorphism. We have seen the first two, now let us see w
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posted @ 2024-07-31 09:19
ZhangZhihuiAAA
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