Capture values from multiple select form and POST via Flask [duplicate] - python-3.x

Question

This question already has answers here:
Converting Flask form data to JSON only gets first value
(2 answers)
Closed 4 years ago.
I need to capture multiple select form vlaue (generated from a MongoDB collection ) and POST via a Flask route to another MongoDB collection: recipes
Below is the relevant form div:
<form action="{{ url_for('insert_recipe') }}" method="POST" class="col s12">
...
<div class="input-field col s6 l6">
<i class="material-icons prefix">warning</i>
<select multiple id="allergen_name" name="allergenlist">
<option value="" disabled selected>Choose allergens</option>
{% for allergen in allergens %}
<option value="{{allergen.allergen_name}}">{{allergen.allergen_name}}</option>
{% endfor %}
</select>
</div>
</div>
...
</form>
I want to capture the selected options and POST them via Flask:
# Get all recipes
#app.route('/get_recipes')
def get_recipes():
return render_template("recipes.html",
recipes=mongo.db.recipes.find())
# Render HTML form
#app.route('/add_recipe')
def add_recipe():
return render_template('addrecipe.html',
users=mongo.db.users.find(),
allergens=mongo.db.allergens.find(),
cuisines=mongo.db.cuisine.find(),)
# Send the form
#app.route('/insert_recipe', methods=['POST'])
def insert_recipe():
recipes = mongo.db.recipes
recipes.insert(request.form.to_dict())
return redirect(url_for('get_recipes'))
However, only the first selected option is being captured and sent.
Any help would be appreciated.
EDIT:
When looking at: http://werkzeug.pocoo.org/docs/0.12/datastructures/#werkzeug.datastructures.MultiDict.to_dict
... relaised that I need to set to_dict(flat=false) in order to have all values of dict returned.

Answer 1

See EDIT above, the correct way is to:
# Send the form
#app.route('/insert_recipe', methods=['POST'])
def insert_recipe():
recipes = mongo.db.recipes
recipes.insert_one(request.form.to_dict(flat=False))
return redirect(url_for('get_recipes'))
Also, just found a duplicate as notified by #davidism :
Converting Flask form data to JSON only gets first value