Import a file from HTML form with cherrypy

Question

I don't know much about the CherryPy framework, but I would like to use it to give an easy way to use python scripts in my lab.

I would like to submit a file from a form so that python can read it and use it, but that doesn't work. Here is my code :

Python

env = Environment(loader=FileSystemLoader("templates"))

def render_html(html_file, **kwargs):
    template = env.get_template(html_file)
    return template.render(**kwargs)

def fasta_reader(df):
    current_line= ""
    while not current_line.startswith(">"):current_line=df.readline().strip()
    id_seq=current_line
    sequence= ""
    while True:
        current_line=df.readline().strip()
        if current_line.startswith(">"):
            yield(id_seq, sequence)
            id_seq=current_line
            sequence = ""
        elif current_line!= "":sequence+=current_line
        else:
            yield(id_seq,sequence)
            break


def protein_search(target, file):
    result = ""
    prot_not_found = True
    for id_seq, seq in fasta_reader(df):
        if target in id_seq:
            prot_not_found = False
            for txt in id_seq, seq:
                result += txt + "\n"
        
    if prot_not_found:
        return f"La protéine {target} n'a pas été trouvée dans le fichier {file}.\n"

    return result


class WebApp:
    def __init__(self):
        pass

    @cherrypy.expose
    def index(self):
        return render_html('index.html')

    @cherrypy.expose
    def form_protein_search(self):
        return render_html('prot_search_form.html')

    @cherrypy.expose
    def process_protein_search(self, prot_name, input_file):
        result = protein_search(prot_name, open(input_file, 'r'))
        *input_filename, format = input_file.split('.')
        result_filename = f"'_'.join({prot_name.split()})_in_{'_'.join(input_filename)}.fasta"
        return render_html('result.html', action=f'la recherche de la protéine {prot_name} dans le fichier {input_file}', result=result, filename=result_filename)

HTML

{% extends 'base.html' %}

{% block title %}Recherche de protéine{% endblock %}

{% block content %}
<h1>Recherche d'une protéine dans une banque au format fasta</h1>
<form action="/process_protein_search" method="post" enctype="multipart/form-data>
    <label for="prot_name">Nom de la protéine:</label><br>
    <input type="text" id="prot_name" name="prot_name"><br>
    
    <label for="input_file">Fichier FASTA:</label><br>
    <input type="file" id="input_file" name="input_file" accept=".fasta, .fa"><br>
    
    <input type="submit" value="Rechercher">
</form>

{% endblock %}

Can someone help me ?

I tried to open the file in my protein_search function and in my process method. Moreover, the file is searched in my working directory, but I want to create a server so that many poeple can use it.