Flask Tutorial Part 5: Handling Forms and User Input

📝 Creating a Simple HTML Form

You can include an HTML form in your template to collect user input:

<form method="POST">
  <label>Name: </label><input type="text" name="username"><br>
  <input type="submit" value="Submit">
</form>

📥 Handling POST Requests in Flask

Flask allows you to handle GET and POST requests using the methods parameter in @app.route().

from flask import Flask, request

app = Flask(__name__)

@app.route("/submit", methods=["GET", "POST"])
def submit():
    if request.method == "POST":
        username = request.form["username"]
        return f"Hello, {username}!"
    return '''
        <form method="POST">
            <label>Name: </label><input type="text" name="username"><br>
            <input type="submit" value="Submit">
        </form>
    '''

🧠 Understanding request.form

request.form is a dictionary-like object that contains form data submitted with the POST method.

📌 Summary

• Use HTML <form> to collect user input.
• Use methods=["GET", "POST"] to handle both types of requests.
• Use request.form["fieldname"] to get form values.