Backend-Cheat-Sheet

1. Linux Commands
2. Python
3. MongoDB

Linux/Unix

The primary development environments for most backends is linux. MacOS are similar to Linux (both track their origins from Unix). Macs will be able to run many of the commands that linux uses.

People with windows

Install the Ubuntu sub system see here: https://docs.microsoft.com/en-us/windows/wsl/install-win10\

Basic Commands

ls Lists all files/folders in your current folder

cd <Folder that exists in your current folder> "Change Directory" Changes current folder to another folder in your current folder

nano Simple commandline based text editor

python <filename> runs basic python files, without a filename it will open a python shell where you can run python code directly in terminal

man get the manual for any command

Package Manager

On Ubuntu your package manager will be the pre-installed apt-get command

For macs follow this to install the package manger brew: https://brew.sh/

Python

Setting Up Python

Setup pip

pip is a package manager for python that allows you to install useful libraries to make your life easier

First check if pip is already installed, and if so skip this part of setup. To check if pip is installed run:

pip -V

If there is an error the follow the below steps:

Mac

Follow this tutorial to download and run the install script https://pip.pypa.io/en/stable/installing/#installing-with-get-pip-py

Ubuntu/Ubuntu Subsystem

To install pip on Ubuntu run:

sudo apt-get install python-pip

VirtualEnv

Using Virtual Environments

Virtual Environments are a sub version of your python install. It allows you to install and use packages without worrying about conflics with your root environment.

Creating a new Virtual environment

python3 -m venv <Name of environment you want to create>

Entering a virtual environment

source <Name of environment>/bin/activate

Flask

Flask is the web server framework we will be using to run web servers using python

Installing Flask

pip install flask

Launching Flask Server

export FLASK_APP=<Server file name> && flask run

MongoDB

Database we will use for persistent storage of data

Install MongoDB

MacOS

brew tap mongodb/brew
brew install mongodb-community

Ubuntu

If you are using windows sub system this will be added later once issues are resolved But you can try this: https://docs.mongodb.com/manual/tutorial/install-mongodb-on-ubuntu/

Running Mongo Server

mongod Launches a mongoDB server using the default configuration only accessable on your machine

Running Mongo Shell

mongo Opens a shell to run mongoDB commands on the server you are running with mongod

Python MongoDB library

pip install pymongo