FloatField - Django Forms - GeeksforGeeks

13 Feb, 2020
FloatField in Django Forms is a integer field, for taking input of floating point numbers from user. The default widget for this input is NumberInput.It normalizes to: A Python float. It validates that the given value is a float. It uses MaxValueValidator and MinValueValidator if max_value and min_value are provided. Leading and trailing whitespace is allowed, as in Python’s float() function.
FloatField has following optional arguments:
max_length and min_length :- If provided, these arguments ensure that the data is at most or at least the given length.
Syntax
field_name = forms.FloatField(**options)
Illustration of FloatField using an Example. Consider a project named geeksforgeeks having an app named geeks.
Refer to the following articles to check how to create a project and an app in Django.
How to Create a Basic Project using MVT in Django?
How to Create an App in Django ?
Enter the following code into forms.py file of geeks app.
from django import forms  # creating a form class GeeksForm(forms.Form):    geeks_field = forms.FloatField( )
Add the geeks app to INSTALLED_APPS
# Application definition  INSTALLED_APPS = [    'django.contrib.admin',    'django.contrib.auth',    'django.contrib.contenttypes',    'django.contrib.sessions',    'django.contrib.messages',    'django.contrib.staticfiles',    'geeks',]
Now to render this form into a view we need a view and a URL mapped to that URL. Let’s create a view first in views.py of geeks app,
from django.shortcuts import renderfrom .forms import GeeksForm  # Create your views here.def home_view(request):    context = {}    context['form'] = GeeksForm()    return render( request, "home.html", context)
Here we are importing that particular form from forms.py and creating an object of it in the view so that it can be rendered in a template.Now, to initiate a Django form you need to create home.html where one would be designing the stuff as they like. Let’s create a form in home.html.
<form method="POST">    {% csrf_token %}    {{ form.as_p }}    <input type = "submit" value = "Submit"></form>
Finally, a URL to map to this view in urls.py
from django.urls import path  # importing views from views..pyfrom .views import home_view  urlpatterns = [    path('', home_view ),]
Let’s run the server and check what has actually happened, Run
Python manage.py runserver
Thus, an geeks_field FloatField is created by replacing “_” with ” “. It is a field to input floating point numbers from the user.
FloatField is used for input of float numbers in the database. One can input date of Marks, percentage, etc. Till now we have discussed how to implement FloatField but how to use it in the view for performing the logical part. To perform some logic we would need to get the value entered into field into a python string instance.In views.py,
from django.shortcuts import renderfrom .forms import GeeksForm  # Create your views here.def home_view(request):    context = {}    if request.method == "POST":        form = GeeksForm(request.POST)        if form.is_valid():            temp = form.cleaned_data.get("geeks_field")            print(type(temp))    else:        form = GeeksForm()    context['form'] = form    return render(request, "home.html", context)
Let’s try something other than a number in a FloatField.
So it accepts a valid float number input only otherwise validation errors will be seen. Now let’s try entering a valid floating number into the field.Float data can be fetched using corresponding request dictionary. If method is GET, data would be available in request.GET and if post, request.POST correspondingly. In above example we have the value in temp which we can use for any purpose. Let’s check what type of temp variable is ?
Core Field arguments are the arguments given to each field for applying some constraint or imparting a particular characteristic to a particular Field. For example, adding an argument required = False to FloatField will enable it to be left blank by the user. Each Field class constructor takes at least these arguments. Some Field classes take additional, field-specific arguments, but the following should always be accepted:
NaveenArora
Django-forms
Python Django
Python
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