Create Arithmetic Calculator
To create an arithmetic calculator using request arguments in Flask, we can follow these steps:
- Create a new file calculator.py and define a route for the calculator in Flask app. This route will accept request arguments for the numbers and operation to be performed. For example:
Python3
@app.route('/calculate')def calculate(): # Get the first operand using request arguments a = request.args.get('a') # Get the Second operand using request arguments b = request.args.get('b') # Get the operation to be perform operator = request.args.get('operator') |
- Now, the parameters we have are in string type. To convert them to integers we can use the int() function. Also, we will ensure that the arguments should not empty.
Python3
# Make sure that the request arguments are not empty if a and b and operator: # Convert the request arguments to integers a = int(a) b = int(b) |
- Use an if statement to determine which operation to perform based on the value of the operator request argument. We can use the standard arithmetic operators (+, -, *, /) to perform the desired operation.
Python3
# Perform the requested operation if operator == 'add': result = a + b elif operator == 'subtract': result = a - b elif operator == 'multiply': result = a * b elif operator == 'divide': result = a / b |
- Finally, Return the result of the operation to the user. Otherwise, if any argument is missing in the URL then return the “Error: Insufficient arguments”
Python3
return f'{a} {operator} {b} = {result}'else: return 'Error: Insufficient arguments' |
Here is a Complete code:
Python3
from flask import Flask, requestapp = Flask(__name__)@app.route('/calculate')def calculate(): # Get the first operand using request arguments a = request.args.get('a') # Get the Second operand using request arguments b = request.args.get('b') # Get the operation to be perform operator = request.args.get('operator') # Make sure that the request arguments are not empty if a and b and operator: # Convert the request arguments to integers a = int(a) b = int(b) # Perform the requested operation if operator == 'add': result = a + b elif operator == 'subtract': result = a - b elif operator == 'multiply': result = a * b elif operator == 'divide': result = a / b return f'{a} {operator} {b} = {result}' else: return 'Error: Insufficient arguments' app.run() |
To use this calculator, we can send a GET request to the ‘/calculate’ endpoint with the request arguments ‘a’, ‘b’, and ‘operator’.
For example, to add 2 and 3, we can send a request like this:
http://localhost:5000/calculate?a=2&b=3&operator=add
To Multiply 4 and 7:
http://localhost:5000/calculate?a=2&b=3&operator=multiply
Similarly, we can perform Subtraction and Division.
If any of the arguments are missing in the URL, Like
http://localhost:5000/calculate
Or
http://localhost:5000/calculate?a=2&b=3
Using Request Args for a Variable URL in Flask
This article will teach us how to use Request Arguments in our Flask application. First, we will understand. What are the Request Arguments?