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1)Nothing Happened by pass Sometimes you need to do nothing. This may not be very often, but when it happens, it's good to know that you have the pass statement:>>> pass>>>another example:

1) rise exceptionTo raise an exception, you use the raise statement with an argument that is either a class (which should subclass Exception for the "catch clause") or an instance.>>> raise Ex

Consrtuctor is one of the so called "magic methods" in python. What separates constructors from ordinary methods, is that the constructors are called automatically right after an object has been cre

First, you shoud keep in mind that standard input/output is one of the best way to check bug. Because the data they offer is raw.These are actually files (or file-like objects), and you can apply

Generators are relatively new to Python, and are (along with iterators) perhaps one of the most powerful features to come along for years.The following example is a function that flattens nested l

First, consider the following Rectangle class:class Rectangle: def __init__(self): self.width = 0 self.height = 0 def setSize(self, size): self.width, self.

The with statement is actually a quite general construct, allowing you to use so-called context managers. A context manager is an object that supports two methods: __enter__ and __exit__. Like:c

class Calculator: def calculate(self, expression): self.value = eval(expression)class Talker: def talk(self): print 'Hi, my value is', self.valueclass TalkingCalculat

1) get some class infothe following example show basic inheritanceclass Filter: def init(self): self.blocked = [] def filter(self, sequence): return [x for x in s

we have to keep in mind that the meaning of class definitions are simply code sections that are executed !>>>class C: print 'Class C being defined...'Class C being defined...>>>class Me

1) method and functionOne big difference between methods and other functions is that methods always receive the object they are part of as their first argument, usually called self.>>> class Class

1)positional,keyword and default parameterFor positional parameters,values are assigned to different parameters according to their positions;  def hello_1(greeting, name): print '%s, %s!' %

The problem of shadowingReading the value of global variables is not a problem in general, but one thing may make it problematic. If a local variable or parameter exists with the same name as the gl

Python has several functions that can be useful when iterating over a sequence (or other iterable object). Some of these are available in the itertools module , but there are some built-in functions

First you must keep in mind that modules are used to define things and reuse code.1) the .pyc fileWhen you import a module, you may notice that a new file appears, like c:\python\hello.p