Python

SliceFor the list or tuple, to take part of the elements, with the loop to achieve more trouble, can be easily done with slices .>>> L = list (range) >>> l[0, 1, 2, 3, ..., 99]First 10 numbers:>>> l[:10][0, 1, 2, 3, 4, 5, 6, 7, 8, 9]0 can be omitted

# General Parameters: in strict accordance with the smooth, the actual parameters are assigned to the formal parameters# def send (name):# ...# Send ("Eric")def sendmail (MAIL_ADDR):#第一步, create function (MAIL_ADDR is formal parameter) step

First, Function Import1. Provide aliases for the module>>> Import Math as Foobar #设置math alias Foobar>>> Foobar.sqrt (4)Showing: 2.02. Provide aliases for functions>>> from math import sqrt as Foobar>>> Foobar (4)Showing: 2.0Second, assign the value1

transferred from: http://blog.jkey.lu/2013/03/15/python-decorator-and-functools-module/What is an adorner?The first time you see a decorator in the Python language makes you think of the decorative patterns in design patterns--dynamically adding

Python's yield keyword Many people may not be very familiar with, the first to know that the keyword is to look at Xrange's document, which mentions yield. Later began to use Tornado, Tornado asynchronous mode of interest, also turned a tornado

fromoperatorImportItemgetter#Itemgetter used to go to the key in Dict, eliminating the use of lambda functions fromItertoolsImportGroupBy#Itertool also contains a number of other functions, such as combining multiple lists together.

Transferred from: http://www.crifan.com/python_already_got_correct_encoding_string_but_seems_print_messy_code/BackgroundThe character encoding in Python is actually a bit complicated.In addition, different development environments and tools, the

Execute system commandThe relevant modules and functions that can execute shell commands are: Os.system os.spawn* os.popen*--Waste popen2.*--Waste commands.*-Discarded, removed in 3.x 1 Import commands 2 3 result =

Hashlib module of common modulesFor cryptographic related operations, the 3.x replaces the MD5 module and the SHA module, mainly providing SHA1, SHA224, SHA256, SHA384, SHA512, MD5 algorithmImport= md5.new () hash.update ('admin')Print

Read the book "Python Network Data Collection" At night and see the code that reads PDF content, remembering the days before collection of Search customers just released a crawl rule that crawls the PDF content of a Web page , and this rule applies

Word2vec IntroductionWord2vec official website : https://code.google.com/p/word2vec/ Word2vec is an open source tool for Google that calculates the distance between words and words based on the set of words entered. It transforms the

the python operator1. Arithmetic operation:2. Comparison operation:3. Assignment Operation:4. Logical Operation:5. Member Arithmetic:Basic data types for Python1. Digitalint (integral type)On a 32-bit machine, the number of integers is 32 bits and

Http://stackoverflow.com/questions/3190706/nonlocal-keyword-in-python-2-x---answer----Python can read nonlocal variables in 2.x, just not the change them. This was annoying, but can work around it. Just Declare a dictionary, and store your

Python getopt module, which is a function specifically designed to handle command-line arguments getopt (args, shortopts, longopts = []) parameters args are generally sys.argv[1:]shortopts short format (-)On the command line, enter:Python

I want Python to print something like "Loading ... ", each period prints out a 0.5-second interval between their sleeping time andImplementation method: 1234567891011 #!/bin/env python# -*- coding:utf-8 -*-import sysfrom time import

Very unexpectedly, my blog actually someone visited, there is a man to evaluate, praise, inexplicable gratitude 650) this.width=650; "src=" Http://img.baidu.com/hi/jx2/j_0063.gif "alt=" j_0063. GIF "/>A list name = ["AAA", "BBB", "CCC", "ddd", "Eee",

11. ancestor of python, 11. ancestor of python According to my previous learning methods, first let's take a look at help (tuple) to see which built-in methods are available.Help on class tuple in module _ builtin __: class tuple (object) | tuple ()-

Python [4]-functions, python FunctionsI. define functions Define a function to usedefStatement, write the function name, parameters in parentheses, and colons in sequence:Then, write the function body in the indent block. The return value of the

Phantomjs captures the rendered JS webpage (Python code), phantomjspython Recently, a website needs to be crawled, but the pages are generated after JS rendering. The common crawler framework is not fixed, so I thought of using Phantomjs to build a

Python uses the lxml module and Requests module to capture HTML pages. Web captureThe Web site uses HTML description, which means that each web page is a structured document. Sometimes it is useful to retrieve data from it while maintaining its