Python

The python built-in functions now need to know as follows:Code: #!/usr/bin/env python #-*-coding:utf-8-*- # author by LH #map (functions, objects that can be iterated) Def F1 (x): return x+100 Ret=map (f1,[1,2,3,4,5]) for i in RET:

The first backtesting program written in Python2016-08-061 defSavfig (Figureobj, fn_prefix1='Backtest8', fn_prefix2='_1_'):2 Importdatetime3fmt='%y_%m_%d_%h_%m_%s'4now =Datetime.datetime.now ()5Fname_savfig = fn_prefix1 + fn_prefix2 +

The content of this section list, tuple operations String manipulation Dictionary operations Collection operations File operations Character encoding and transcoding I. operation of lists and tuplesThe list is one

Python randomly generated verification code method there are many, today to you list two kinds, we can also be modified on this basis, the design of the appropriate verification Code method method one: Using RangePython random generation of

OpenCV do not need to say more, first recommend a force tutorial:Https://opencv-python-tutroals.readthedocs.io/en/latest/py_tutorials/py_tutorials.htmlThe example of tutorial is realized once, can have a basic understanding of OPENCV, but to do some

Today, say the decorator.In the Python language, the main function of adorners is to reduce the essence of repetitive input. With an adorner, you can use repetitive code very intuitively and elegantly, like a dress that can be worn to the emperor or

A moduleA module is a code that someone else has written and can be referenced by an import. A standard library is a library that is officially released by Python and is installed by default when you install Python.1.osand system-related, such as:>>>

Previous article, introduced a very fast sorting algorithm-bucket sequencing, but its disadvantage is too much resources, this time to implement the algorithm will not use too much resources, it is bubble sort. Questions raised:Sort the

Reprinted from: http://www.cnblogs.com/sislcb/archive/2008/12/01/1344861.html e-mail module to generate email is also very simple, Just need some basic knowledge of mime. Let's look at a bit of MIME basics below. mime message consists of the

In Python, an object assignment is actually a reference to an object. When you create an object and then assign it to another variable, Python does not copy the object, but simply copies the object's reference.1. Assigning ValuesThe assignment is

Object-oriented programming of Python advanced features (classes and objects)First, Class and object:Process-oriented and object-oriented programmingProcess-oriented programming: Functional programming, C-programs, etc.Object-Oriented Programming: C+

Member operatorsPython has a member operator that can determine whether an element is in a sequence. For example, you can tell if a character belongs to the string, you can tell if an object is in the list, and so on.The syntax for using member

Using the functions in Sklearn makes it easy to divide the data into trainset and TestsetThe function is Sklearn.cross_validation.train_test_split and uses the following:Import NumPy as NP from Import train_test_split>>> X, y = Np.arange (Ten).

The day before yesterday installed in CentOS python2.7.12 and python3.5.2, today to install two versions of PIP, from the official download get-pip.py, using Python get-pip.py, error, unable to install. By looking for the reason, it was finally

There has always been a great interest in compilers and parsers, as well as the concept of a compiler and the overall framework, but it is not well understood in the detail section. The program source code that we write is actually a sequence of

[Python development practice] Windows 7 + VirtualBox + Ubuntu environment configuration, virtualboxubuntu 1. VirtualBox Installation Refer to the general installation method. VirtualBox 4.3.14 for Windows hosts:

Use try, cmdt, and else To make the Python program more "strong", using tpython In the executed program, fatal errors may occur due to some reasons, such as input and output (for example, the input file name is incorrect and the relevant Code cannot

Summary of the usage of the urllib2 module in Python network programming, pythonurllib2 I. Basic Applications import urllib2url = r'http://www.baidu.com'html = urllib2.urlopen(url).read()print html The client communicates with the server through

Python string formatting output (format/printf) and pythonprintf For Python string formatting, use "character % format 1% Format 2 characters" % (variable 1, variable 2), and % format to accept the type of the variable. A simple example is as

The django model creates a new object and obtains an object. You can create an object using the following methods: Person. objects. create (name = name, age = age) P = Person (name = "WZ", age = 23)P. save () P = Person (name = "TWZ ")P. age = 23