Troubleshooting SMILES Server with Flask and RDKit

SmilesServer.py

#!/usr/bin/env python3

from flask import Flask, request, make_response

from rdkit import Chem, rdBase
from rdkit.Chem import rdDepictor
from rdkit.Chem.Draw import rdMolDraw2D

app = Flask(__name__)

# Flask example: https://github.com/rduplain/flask-svg-example/blob/master/app.py
# svg generation: http://rdkit.blogspot.de/2015/02/new-drawing-code.html

@app.route('/pic.svg')
def draw_smiles():
    #print(request.args)
    smiles = request.args.get("smiles", "C=CC=O")
    width = request.args.get("width", 400)
    height = request.args.get("height", 200)
    
    
    try:
        smiles = smiles.strip()
        mol = Chem.MolFromSmiles(smiles)
        rdDepictor.Compute2DCoords(mol)
        drawer = rdMolDraw2D.MolDraw2DSVG(width, height)
        drawer.DrawMolecule(mol)
        drawer.FinishDrawing()
        svg = drawer.GetDrawingText().replace('svg:','')
        
        # maybe cut off the first line with xml tag?
        #svg = "\n".join(svg.split("\n")[1:]) 
        
        response = make_response(svg)
        response.content_type = 'image/svg+xml'
        return response
        
        
        
    except:
        return "invalid input: " + smiles

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

or more generally, I had the route as @app.route('/<smiles>') and smiles as the argument to draw_smiles rather than getting it as an argument from request