scrapy for python 3

Python basics [Article 3], python Article 3 Def function name (parameter):... function body... Functions are defined as follows: Def: indicates the function keyword. Function Name: name of the function. The function will be called Based on the function name in the future. Function body: perform a series of logic

Python Study Notes 3-strings, python Study Notes 3- Format String/compound field name >>> import humansize>>> si_suffixes = humansize.SUFFIXES[1000]>>> si_suffixes['KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB']>>> '1000{0[0]} = 1{0[1]}'.format(si_suffixes)'1000KB = 1MB' >>> import humansize>>> import sys>>> '1MB = 10

3 methods for installing third-party libraries in Python, 3 methods for installing third-party libraries in python [Method 1]: Use setuptools to install the python module. First download http://peak.telecommunity.com/dist/ez_setup.py NOTE: It is best to download a setuptools

Original link: http://www.kuqin.com/shuoit/20140728/341451.html Many Python beginners want to know which version of Python they should start learning from. My answer to this question is "you learn the version of the tutorial you like and then check the differences between them." " But what if you start a new project and have a choice? I would like to say that there is no right or wrong

Python note-3 (Purchase Product), python-3 #! /Usr/bin/env python#-*-Coding: UTF-8 -*-# The following is a shopping program:# First enter the salary, display the commodity list, purchase, quit, and finally format and output the purchased commodity.Count = 0While True: # make

Python 3 iterator and Python 3 Generator 1 ''' 2 generators are all iterators. The iterator is not necessarily generator 3''' 4 5 # list1 = [1, 2, 3, 4, 5] 6 # p1 = iter (list1) # equivalent to _ iter _ () 7 # print (p1) 8 # prin

is {' N1 ': ' Nikita '}50,000 Energy parametersDef f1 (*args, **kwargs)III Other1 Local variables and global variablesOnly local variables are used in the function, all scopes are available as global variables (note capitalization), and global is used in the function, and local variables can be changed.' Lulu ' def F1 (): = Ten # Change the global variable of name to Nikita, the name of the following function is Nikita Global name ' Nikita ' Print (age, NAME)If the global va

3 methods for merging strings in Python and 3 methods for merging strings in python Purpose Merge some small strings into a large string, more consideration is the performance Method There are several common methods: 1. Use the + = OperatorCopy codeThe Code is as follows:BigString = small1 + small2 + small3 +... +

Python 3.x and Python 3.xjson Preface This article mainly introduces some operations of python3 on JSON and shares them for your reference. I will not talk about them here. Let's take a look at the details. 1. Convert Dictionary to JSON Convert dict to JSON. The json package is used here. Import jsonaItem = {} aItem ["

standard Library, as well as binary forms of various platforms, can be obtained from the official Python website: https://www.python.org/free of charge, and you are free to spread these things.The site also contains suggestions from many people about the modules, programs, and tools that face Python 3, as well as a variety of additional documentation. The

Python learning notes (8) Python list (3), python learning notes Sequence Sequence: in mathematics, a sequence is an object (or event) in a column. In this way, each element is either before or after another element. The order between elements is very important. Wikipedia Sequence is the most basic data structure in

Note whether the current Python version is 2.X or 3.x,python 3.X has a greater change in the use of super than Python 2.X; 1. Python 2.x Class Contact (object): all_contacts = [] def __init__ (self, Name, email): s

For the Python community, Python 3 is the worst thing. I still remember that when I used Python for the first time, I had been engaged in the C ++ field for a long time. Python is like a bible for me. I can open a text editor. After a few seconds or several minutes, a progra

the difference between Python 2 and Python 3 recently began to learn Python, the process of continuous learning to the difference between the two, in order to facilitate the review, so write here, the content will be constantly updated 1, Encoding: Python2 's default encoding is ASCII, so the default is not supporte

Python learning notes (11) Python statements (3) and python statements While loop statement It is used to execute a program cyclically under a certain condition to process the same task that needs to be processed repeatedly. Syntax: While judgment condition: execution statement ...... The execution statement can be a s

we can also do this by adding \ n to the string:>>> str1 ="List of Name:\nhua Li\nchao Deng" >>> Print (str1) List of Name: Hua Li Chao Deng But that's a lot of confusion when it comes to typing, isn't it? So in this case try to use 3 quotation marks, as for 3 single quotes or double quotation marks are the same, only need to note that if the string contains a single quotation mar

A pit, don't know why, just record it.1 while loop! = 0:2 // omit operation 3 print loop4 if loop = = 0:5 print (ID (loop))6 print (ID (0))Running results in Python 2.7Skip loop printing with loop not 003809311234396768Running results in Python 3.xSkip loop printing with loop non 0 0495

Developed with the old boy's education in Python [Article 3]: Python functions, old boy python Set Unordered, non-repeated, nested.Function Create a function: 1. def Keyword: Create a function 2. Function Name 3 ,() 4. Function body 5. return valuesDefault return val

Python source code analysis Note 3-Python execution PrinciplePython source code analysis Note 3-Python execution Principle The book address: http://www.jianshu.com/p/03af86845c95 I have written several source code analysis notes before. However, if I feel that I have not

... One of the most important advantages of Python 2 is that it has a large number of third-party libraries that can be used to do anything, but Python 3 doesn't have that advantage. Admittedly, there are a lot of libraries that have been ported to Python 3, but there are mo