image_upload/upload.py

import os
from flask import Flask, render_template, redirect, request
from flask_wtf import FlaskForm
from flask_wtf.file import FileAllowed, FileField
from wtforms import (
    SubmitField,
)

# config me here
APP = Flask(__name__, static_folder="static")
APP.config["IMAGE_FOLDER"] = "static/images"
ALLOWED_FILES = ["jpg", "png", "gif", "webp"]

# don't config these lines
APP.config["SECRET_KEY"] = os.urandom(24)

class ImageUploadForm(FlaskForm):
    """Image upload form."""
    image = FileField(
        "image:",
        validators=[FileAllowed(ALLOWED_FILES, f"Images only, please use any of the following file extensions: {(", ").join(ALLOWED_FILES)}")],
    )
    submit = SubmitField("Submit")


def saveimage(image):
    """Save the image to the folder"""
    image.save(os.path.join(APP.config["IMAGE_FOLDER"], image.filename))


@APP.route("/", methods=["GET", "POST"])
def index():
    """Upload route, a page to upload an image"""
    imageuploadform = ImageUploadForm()
    if request.method == "POST":
        if imageuploadform.validate_on_submit():
            saveimage(imageuploadform.image.data)
    return render_template("upload.html", imageuploadform=imageuploadform)


if __name__ == "__main__":
    APP.debug = True
    APP.run(port=5000)