from flask import Flask, render_template, request

app = Flask(__name__)


@app.route('/', methods=['GET', 'POST'])
def index():
    if request.method == "POST":
        # getting input with name = fname in HTML form
        instring = request.form.get("instring")
        outstring = instring.replace(" ", "-")
        return outstring
    return render_template("index.html")


if __name__ == '__main__':
    app.run()