Python

Add by ZHJ: The Python document clearly explains how the default parameters work, as follows"Default parameter values are evaluated when the function definition is executed. This means the expression was evaluated once when the function was defined,

List of Python data structures and tuples Sequence: A sequence is a data structure that contains elements that are numbered (starting at 0). A typical sequence consists of a list, a string, and a tuple. Where the list is mutable (can be modified)

Step 1: Writing mysetup.pyImport py2exe#mysetup.pyfrom distutils.core import setupimport py2exesetup (console=[' hello.py '])Where hello.py is the Python script that you want to packStep 2: Place the mysetup.py and hello.py in the same directoryStep

It is also easy to understand the following slicing behavior, even for novice python:>>> s = ' this_is_a_test ' >>> s[1:5] ' his_ 'Further, the following syntax and output are not difficult to understand:>>> s = ' this_is_a_test ' >>> s[:: 2] '

To write a Python applet, light classmates recommend the sexy sublime text2 +jedi (Python auto-complete plugin).First install sublime Text2 's "plug-in management" plug-in package control:When Sublime is turned on, the key combination "ctrl+~"

RecursiveInside the function, the programming technique called by the program itself is called recursion (recursion). Recursive functions have a clear structure and a very intuitive understanding of the computational process, but there are also

The idea of the algorithm is not much to say. Explain the code mainly.Graph = [[0,4,3,2], [4,0,1,4], [3,1,0,2], [2,4,2,0]]n = 4flags = [True,true,true,true]queue = []#] Flags is the storage node access condition, True for the

In Python, both static and class methods can be accessed through class objects and class object instances. But the difference is: @classmethod is a function modifier, which means that next is a class method, which is called an

　　Python module and package concept : The package contains modules, modules are saved in xxx.py format if a package code is called Import xxx. If you want to specify the module code in the calling package, import the package. Module. Calling a

1. Standard type operator1.1 Comparison of object valuesComparison operators are used for equality of objects of the same type, all built-in types support comparison operations, and comparison operations return a Boolean value of TRUE or False.>>> 2

In the work encountered this function, did not think of any encounter, a look surprised me, this function is very powerful. The following is a brief introduction to its usage.1. Get class variablesClass A: a = 1getattr (A, ' a ') = = 12. Get

Selenium is also a tool for Web application testing. The selenium test runs directly in the browser, just as the real user is doing. Supported browsers include IE (7, 8, 9), Mozilla Firefox, Mozilla Suite, and more. The main features of this tool

Creating ThreadsThe format is as follows Threading. Thread (Group=none, Target=none, Name=none, args= (), kwargs={}) This constructor must be called with the keyword argument-Group Thread groups-Target Execution method-Name thread

If multiple threads are working together on a data modification, unpredictable results may occur, and multiple threads need to be synchronized in order to ensure the correctness of the data.Using the thread object's lock and Rlock allows for simple

Closure in PythonClosure is a function object that references an external variable, regardless of whether the variable's scope exists in the memory. For example, the generate_power_func function returns another function: def generate_power_func (n):

Python Learning (4) Data Structure-dict and pythondictDictionary type dict A dictionary is composed of keys and values. A dictionary is also called an associated array or a hash table.Dict assignment Dict is enclosed in braces {}. Each key and value

Use mysql database in python for details, pythonmysql 1. Install mysql If you are a windows user, mysql installation is very simple. Download the installation file directly and double-click the installation file to proceed step by step. The

[Python] infix expression to prefix expression # Priority def opOrder (op1, op2): order_dic = {'*': 4, '$': 5, '/': 4, '+': 3, '-': 3} if op1 = '(' or op2 = '(': return False elif op2 = ')': return True else: if order_dic [op1] ', infix2prefix

Python finds the nearest color from a set of colors. This example describes how to find the nearest color from a set of colors in python. Share it with you for your reference. The specific analysis is as follows: This code is very useful. You can

In python, log on to zhihu to get my favorites and save it as a word file, This program was completed a long time ago and never been released. I will share it with you if it is not very busy recently.The BeautifulSoup module and urllib2 module are