Python

1. Installing PymysqlPIP3 Install Pymysql2. Install the Dbutils Open Source Tool LibraryPIP3 Install Dbutils3. Mode one: fromDbutils.persistentdbImportPersistentdbImportPymysqlpool=Persistentdb (creator=pymysql,#modules that use linked

Collections ModuleThe Collections module provides several additional data types based on the built-in data types (dict, list, set, tuple): Chainmap, Counter, deque, Defaultdict, Namedtuple and Ordereddict and so on.1.namedtuple: Generates a tuple

Installing Virtualenv$ sudo pip install virtualenvThen create a test directory:$ mkdir testvirtual$ cd testvirtualYou can successfully create a virtual environment ENV1:$ virtualenv env1 You can successfully create another virtual environment env2:$

Yes3Dictionary method, which returns a list-like value, corresponding to the dictionary's key, value, and key-Value pairs:Keys ()、VALUES ()AndItems ()。 The values returned by these methods are not real lists, they cannot be modified, noAppend ()

First, learn the history of Python and some nounsExplanatory language: Side compilation Edge executionCompiled language: first compiled and executed such as C,pythonDynamic languages: No need to declare variable types, Eg:python RubyStatic language:

Abnormal, should not exist, but we sometimes encounter such a situation, such as when we monitor the server, every second to collect information, then one second did not collect the information we want, but the next second acquisition, and then

In order to speed up learning python3.x so directly to see a lot of practical small projects, looked up a lot of information after writing this script, this script is to crawl Baidu Image ' Oriental Fantasy township ' pictures, but found a few

1. Regular expressions?? Regular expressions provide the basis for advanced text pattern matching, extraction, and/or textual search and replace functions, and simply, regular expressions are strings of characters and special symbols. Python

Basic knowledge Exercises (I.)1. Two ways to execute a python script(1). Interactive mode: Start the Python interpreter and execute the command (2). Scripting: Python xxx.py or chmod +x &&./xxx.py2. Briefly describe the relationship between bits and

Json.dumps is the encoding parsing of a Python data type list in JSON format,Examples are as follows:Import # import JSON modules in Python # Create an L list # A list of L, JSON format encoding Print repr (L) Print # Output ResultsThis allows us to

Python can perform simple calculator functions: such as >>2+2 ==> 4,1/2==>0.5 or write 1/2.0==>0.5 (take float) 1//2 ==>0 ("//" will force rounding) -3**4 ==>- 81 (Power function operation level is higher than the first operation, similar to ==>-(3**

1. Examples of scripts that recursively list files in a directoryThe list of files in the directory can be done by using the following method:Os.listdir ()In [1]: import OSIn [4]: os.listdir ('/root ')OUT[4]:['. TCSHRC ','. Bash_history ','. BASHRC '

Take the watercress as an example, visit https://www.douban.com/contacts/list to see who you care about, and log in to view it.If you use the Requests.get () method to get this HTTP, no login can only catch a login interface, so we have to use

Continue with the previous section, in this section we will establish a user registration and authentication system that allows users to register their accounts and log in and out. We will create a new application that contains all the features

Get OS information:1=" ".join(platform.linux_distribution())2= subprocess.call([‘cat‘‘/etc/redhat-release‘])Get host PlatformGet host Nameimport sockethostname = socket.gethostname()Get CPU information: Get the number of physical CPUs1. os.cpu_count(

In the test interface, there will be such a scenario, input illegal parameters, check the return error code and error contentThe usual practice is to send a request, the wrong return result is taken out, and then the comparison match; but there is a

1, first because the Mac comes with Python, version is python2.7.102, install PIP, because already have, so can not use brew install. Here with sudo easy_install pip3, install beatifulsoup4,sudo-h PIP installs Beautifulsoup4. BeautifulSoup is a

1, the variable of the function2, the return value of the function1, the variable of the functionThe variables of the function are divided into local variables and global variables.This x is a local variable, and after the function is executed, the

Flask framework,A Brief Introduction to the FLask framework Flask is a micro-framework developed based on Python and dependent on the jinja2 template and the Werkzeug WSGI service. For Werkzeug, it is essentially a Socket server, which is used to

Python learning diary: day15: ------ built-in functions, pythonday15 1. Scope-related 1) locals () --------- obtain the dictionary of local variables in the namespace in which the method is executed # Return all names in the local scope 2) globals ()