ModuleNotFoundError: No module named 'forms'

You're probably importing LoginForm in views.py as following:

from forms import LoginForm

Change that to

from .forms import LoginForm

It sounds like it should be working, you might want to post the full error and more of your code. Something like this should be working

# forms.py
from django import forms


class LoginForm(forms.Form): 
    email = forms.EmailField(label='Courriel')
    password = forms.CharField(label='Mot de passe',
                        widget = forms.PasswordInput)

and the views

# views.py
from forms import LoginForm
from django.shortcuts import render


def someview(request):
    if request.method == 'POST':
        login_form = LoginForm(data=request.POST)
        if login_form.is_valid():
            # do something when valid
    else:
        login_form = LoginForm()
    return render(request, 'login.html', {'login_form': login_form})

where you have a folder structure like

/app/
   forms.py
   views.py