How to use the flask.request function in Flask

def login():
    form = LoginForm()
    if form.validate_on_submit():
        try:
            user_token = client.login(form['username'].data, form['password'].data)
            if not validate_permissions(user_token['perms']):
                perms = REQUIRED_PERMISSIONS
                msg = 'Invalid permissions, saltpad needs {0} for user {1}'.format(perms, form['username'].data)
                flash(msg, 'error')
            else:
                session['username'] = form['username'].data
                session['user_token'] = user_token['token']
                flash('Hi {0}'.format(form['username'].data))
                return redirect(request.args.get("next") or url_for("index"))
        except Unauthorized:
            flash('Invalid credentials', 'error')

    return render_template("login.html", form=form)

def edit(container=None):
    """
    edit containers page and actions if form post request
    """
    host_memory = lwp.host_memory_usage()
    cfg = lwp.get_container_settings(container)

    if request.method == 'POST':
        form = request.form.copy()

        if form['bucket'] != get_bucket_token(container):
            g.db.execute("INSERT INTO machine(machine_name, bucket_token) VALUES (?, ?)", [container, form['bucket']])
            g.db.commit()
            flash(u'Bucket config for %s saved' % container, 'success')

        # convert boolean in correct value for lxc, if checkbox is inset value is not submitted inside POST
        form['flags'] = 'up' if 'flags' in form else 'down'
        form['start_auto'] = '1' if 'start_auto' in form else '0'

        # if memlimits/memswlimit is at max values unset form values
        if int(form['memlimit']) == host_memory['total']:
            form['memlimit'] = ''
        if int(form['swlimit']) == host_memory['total'] * 2:
            form['swlimit'] = ''

def mod_bans():
    ban_messages = []

    if request.method == 'POST':
        ban_form = BanForm(request.form)
        if ban_form.validate():
            ip4 = parse_ip4(ban_form.ban_ip4.data)
            ip4_end_form = ban_form.ban_ip4_end.data
            ip4_end = parse_ip4(ip4_end_form) if ip4_end_form else None

            ban = BanModel()
            ban.ip4 = ip4
            if ip4_end is not None:
                ban.ip4_end = ip4_end
            ban.reason = ban_form.reason.data
            board_form = ban_form.board.data
            ban.board = board_form if board_form else None
            ban.length = ban_form.duration.data * 60 * 60 * 1000

            try:
                ban_service.add_ban(ban)

def track_download(self, event, resource, **kwargs):
        tracker = PiwikQueryTrackDownload()
        resource_url = request.url if isinstance(resource, LocalFile) else resource.getURL()
        resource_title = resource.getFileName() if isinstance(resource, LocalFile) else resource.getURL()
        resource_title = 'Download - {}'.format(resource_title)
        tracker.call(resource_url, resource_title)

def signin():
    username = request.form['username']
    password = request.form['password']
    error = None
    if len(username) < 5:
        error = 'Username must be at least 5 characters'
    if len(password) < 6:
        error = 'Password must be at least 8 characters'
    elif not any(c.isupper() for c in password):
        error = 'Your password needs at least 1 capital'
    if error is not None:
        return jsonify({'r': 1, 'error': error})
    return jsonify({'r': 0, 'rs': 'Ok'})

def restrict_to_role(role):
    if current_user.is_anonymous:
        flash('You are trying to access a protected area. Please log in first.', 'error')
        return redirect(url_for('account.login', next=request.url))

    if not current_user.has_role(role):
        flash('You do not have permission to access this area of the site.', 'error')
        return redirect(url_for('doaj.home'))

def add_at_prefix():
    r = request.get_json()
    if r is not None:
        keys = ['id', 'type']
        for key in keys:
            if r.get(key, False):
                r['@'+key] = r.pop(key)

def is_organisation_name_unique():
    organisation_id, name = check_request_args(request)

    name_exists = Organisation.query.filter(Organisation.name.ilike(name)).first()

    result = (not name_exists) or str(name_exists.id) == organisation_id
    return jsonify(result=result), 200

domain_data=domain_data,
            all_data=constants.DOMAIN_DATA,
            site_tutorial_links=site_links,
            tutorial_data=current_tutorial_data,
            tutorial_data_json=json.dumps(current_tutorial_data),
            domain_data_json=json.dumps(domain_data),
            html_title=html_title,
            language_code=language,
            languages=get_languages(),
            language_names=get_language_names(),
            uid=uid,
            **current_tutorial_data
        ))

    # POST method handling
    data = run_code(request.json["code"], domain_data["language_id"])

    if "output" in current_tutorial_data and current_tutorial_data["output"] == data["output"]:
        data["solved"] = True


    else:
        data["solved"] = False

    return make_response(json.dumps(data))