Basics of flask for creating RESTful web API's

Jayesh Kale — Fri, 12 Jun 2020 05:38:48 +0000

Did you know what flask is?, It's possible that you heard this word at least once if you have something to do with python. If you don't know then you're at right place. This will be three part series in 1st article we will discuss what flask is? and create hellow world app,
in next article we will create sample app called photo bucket explaining creation of project step by step, whereas in futher post we will structure our project. Don't worry if you didn't know any of this term mentioned; i will explain them briefly where ever possible. so lets get started.

Flask

Introduction

what is flask?

Flask is a micro-web framework developed by pallets projects for python to get started with creating api's quickly and easily.

lets break down above to understand more efficiently:

micro meaning line of code for flask framework is less than what others offer. In practical flask doesn't enforce you too use only what flask provide or what should be directory structure. You can even make flask application in single python file or split it into multiple modules, however making application in single python file is not recommended as it will get utterly complex to manage as application grows. Main point to notice here is that flask doesn't come battery included so whats that actually mean? This means that like other framework it doesn't enforce you to only use framework specific ORM/ODM and drivers instead it lets you choose. Okay so lets you choose? suppose you want to include text-search support in your application for that you need search engine such as whoosh, elastic search other than that some databases also provide you with text search like mongodb now the question arises what will work with flask -> all of them. and that's the beauty of this framework.
framework are the piece of code which consist regularly used functionality so you don't have to be code everything from scratch. for example, you use print() function in any language that print function is consist the logic detecting the string and variable as argument and then showing it on screen so you don't have to write everything and that will save your time and boost productivity. So framework are like predefined stuffs for you with some advanced features.

I think you have the idea now what flask is. so you can go to next topic. before that you will have to install flask do it with this command pip install flask

note: flask work on extension to provide extra functionality there are plenty of extension on python package index you can search extension using flask-packagename. to learn more about extension hit this link.

Hello World

app.py

from flask import Flask
app = Flask(__name__)

@app.route('/')
def hello_world():
    return "Hello World!"
if __name__ == "__main__":
    app.run()

importing Flask class from flask module.
We are registering variable app as instance of flask
@app.route is decorator function used to provide path '/' or you can write '/helloworld' after the localhost address.
return statement to output hello world! as string on browser.
app.run() to run application

lets run it.

whoillaa pat on your back you just created api in flask.

Download Flask cheatsheet here

Setting up flutter without Android studio

Jayesh Kale — Tue, 17 Sep 2019 21:05:28 +0000

Sometimes due the hardware constraints or some other reasons developer will prefer light weight solution rather than Big Bulky Android Studio. So heres a good news for you in this article we will configure visual studio code to work with flutter without android studio. We are using ubuntu 19.04 as operating system but you can choose choice of your linux distros. So lets get started....

Packages we required

Installing Packages

We are installing it by following below steps respectively:

Navigate to folder where you downloaded your binaries.
Extract it and move it to relevant location.
Set up path and refresh .profile file to access utilities.

Installing Packages

To set up path open profile type in terminal
$ gedit ~/.profile

Android tools

$ unzip sdk-tools-linux-4333796.zip
$ mkdir Android
$ mv tools/ Android/
$ sudo mv Android/ /usr/lib

#android home
export ANDROID_HOME=/usr/lib/Android
export PATH=$ANDROID_HOME/tools:$PATH
export PATH=$ANDROID_HOME/tools/bin:$PATH
export PATH=$ANDROID_HOME/platform-tools:$PATH

#android sdk root
export ANDROID_SDK_ROOT=/usr/lib/Android
export PATH=$ANDROID_SDK_ROOT:$PATH

Flutter

$ tar xvf flutter_linux_v1.9.1+hotfix.2-stable.tar.xz
$ sudo mv flutter/ /usr/lib

#flutter
export FLUTTER_HOME=/usr/lib/flutter
export PATH=$FLUTTER_HOME/bin:$PATH

Gradle

$ unzip gradle-5.6.2-bin.zip
$ mkdir gradle
$ mv gradle-5.6.2/ gradle/
$ sudo mv gradle/ /opt

#gradle
export GRADLE_HOME=/opt/gradle/gradle-5.6.2
export PATH=$GRADLE_HOME/bin:$PATH

OpenJDK 8

Open synaptic package manager if you don't have it install via

$ sudo apt install synaptic

Type in OpenJDK 8 to search bar.
Select
1. openjdk-8-jdk
2. openjdk-8-jdk-headless
3. openjdk-8-jre
4. openjdk-8-jre-headless
Apply and wait for install. Don't worry it will set up environment variable for you automatically.

Our installation of packages is done use subsequent command to refresh .profile
$ . ~/.profile

Setting up Android environment

For setting Android environment you have to download following packages. I'm Downloading latest one as the date of publishing but you can download many system images to support wide array of devices using sdkmanager.

Note: If you're facing issue with sdkmanager as Warning: Could not create settings then open up terminal and type $sdkmanager --sdk_root=${ANDROID_HOME} tools this will upgrade binaries to latest and everything will works as expected.

$ sdkmanager "system-images;android-29;google_apis;x86_64"
$ sdkmanager "platforms;android-29"
$ sdkmanager "platform-tools"
$ sdkmanager "patcher;v4"
$ sdkmanager "emulator"
$ sdkmanager "build-tools;29.0.2"

Accept all licenses using

sdkmanager --licenses

Setting up flutter config

Update flutter config and set path to android sdk directory where it is installed.

$ flutter config --android-sdk /usr/lib/Android

You have to install flutter extension in visual studio code in order use flutter.

creating Emulator

Create emulator with name pixel or choose the name you want

$ avdmanager -s create avd -n pixel -k "system-images;android-29;google_apis;x86_64"

Create emulator using existing devices features

$ avdmanager -s create avd -n pixel -k "system-images;android-29;google_apis;x86_64" -d 19

you can get list of exting devices using

$ avdmanager list

Moment of truth

$ flutter doctor -v

This command should give all green and ok except android studio path.

Run emulator

$ flutter emulator --launch pixel

Here's an image in action:

DEV Community: Jayesh Kale

Basics of flask for creating RESTful web API's

Flask

Introduction

Hello World

Setting up flutter without Android studio

Packages we required

Installing Packages

Installing Packages

Android tools

Flutter

Gradle

OpenJDK 8

Setting up Android environment

Setting up flutter config

creating Emulator

Moment of truth

Run emulator