• Django v1. X version startup error: syntax error: generator expression must be parentized


    Django v1. X version startup error: syntax error: generator expression must be parentized   Error message: Failed to get real commands on module “mysite”: python process died with code 1: Traceback (most recent call last): File “E:\JetBrains\PyCharm 2020.1\plugins\python\helpers\pycharm\_jb_manage_tasks_provider.py”, line 25, in django.setup() File “E:\PycharmProjects\python\venv\lib\site-packages\django\__init__.py”, line 27, in setup apps.populate(settings.INSTALLED_APPS) File “E:\PycharmProjects\python\venv\lib\site-packages\django\apps\registry.py”, line 85, in populate […]

  • Python interpreter and IPython


    brief introduction Today, I’d like to introduce a very powerful interpreter of python, IPython. Although Python has its own interpreter, IPython is relatively more powerful. Python interpreter Python has its own interpreter. We can enter Python’s interpreter environment by entering Python on the command line: $> python Python 2.7.15 (default, Oct 2 2018, 11:47:18) [GCC […]

  • Why doesn’t Python have a void keyword?


    voidIs one of the most common keywords in programming languages. Literally, it means “empty, empty set, blank”,Most commonly used inRepresents a return value type of a function. Wikipedia has a definition: The void type, in several programming languages derived from C and Algol68, is the type for the result of a function that returns normally, […]

  • Python essay (1): int object pool


    0. Preface The new high school technology textbook in Zhejiang Province will use Python 3 as the information technology teaching language. As a senior one student, I began to review my Python knowledge. Besides review, I specially set up this series to record my review income. The problems mentioned in this note were raised by […]

  • Linux uses alternatives to switch between different versions of the same tool (Python as an example)


    Linux version: CentOS Linux release 7.5.1804 (core)Toolkit: Python 2.7.5 (included). If you want to install Python 3, you can switch 1: Configure environment: 1. Check the directory of installed Python 2.7.5 Installation path:[[email protected] ~]# whereis pythonpython: /usr/bin/python /usr/bin/python2.7 /usr/lib/python2.7 /usr/lib64/python2.7 /etc/python /usr/include/python2.7 /usr/share/man/man1/python.1.gz Executable path:[[email protected] ~]# which python/usr/bin/python View soft connections:[[email protected] alternatives]# ls -l /usr/bin/python*lrwxrwxrwx […]

  • Learning and sorting of Linux shell script


    1、 Understand Shell Scripting Language Shell script is a program written in C language. When the shell program is executed, the bottom layer will execute the logic code of C language. Shell is not only a command line language, but also a programming language. 1.1 header file #!bin/bash xx The first line of the file […]

  • Emacs LISP (4) — variable


    1、 Reference Emacs series article directory – updating 2、 Variable 2.1 variable A variable consists of a symbolsymbolValues bound to symbolsvalueThe bound value can be Type of value Example numerical value 10 character string “such as this” list ‘(spruce pine oak) Function definition 2.2 possible errors in explanatory variables (1) Variables are treated as function […]

  • Making games with Python & pyGame Chinese Translation


    Making games with Python & pyGame playing games with pyGame Chapter 1 – installing Python and pyGame Original author: Al sweigartTranslation: bigbigbli / Li ChaoReprint prohibited What should you know before you start playing games? Before reading this book, it may be helpful if you have a little understanding of Python Programming (or how to […]

  • Installing Tomcat service for Ubuntu


    environment Linux/Ubuntu20.04LTS Tomcat8.5.68 technological process Download the Tomcat service installation package,https://tomcat.apache.org/dow…, select the version you want to download. The version you want to download here is 8.5, and the compressed package in tar.gz (PGP, SHA512) format. Enter the download directory, open the terminal, start decompressing the downloaded compressed package and decompress it to the user’s […]

  • Pycharm Chinese tutorial 01: four ways to run Python


    Online reading of pycharm Chinese Guide:http://pycharm.iswbm.com/GitHub project home page:https://github.com/iswbm/pych… 1. Set Python interpreter Pycharm only provides an integrated development environment. You still have to rely on the Python interpreter when executing Python programs. There can be multiple versions of Python interpreters on a computer, so before you execute a python program, you must first tell […]

  • How to start ASM normally?


    Python ide pycharm1) Integrated development environment (IDE)IDE (integrated development environment) integrates most of the tools needed to develop software. It generally includes the following tools: graphical user interfaceCode editor (support code completion / Auto indent)Compiler / interpreterDebugger (breakpoint / step)…… 2) Pycharm introductionPycharm is an excellent integrated development environment for PythonPycharm can be used in […]

  • The difference between Python 2 and python 3


    Statement: the following is my personal understanding. If you find any mistakes or questions, you can contact me for discussion brief introduction At present, there are two Python versions of projects developed with Python, namely, python 2. X and python 3. X. because Python 3 has a large upgrade compared with Python 2, python 3 […]