saeed.py

import scrapy
from scrapy.http import FormRequest


class SaeedSpider(scrapy.Spider):

    name = 'saeed'

    start_urls = [
        'https://seffaflik.epias.com.tr/transparency/uretim/gerceklesen-uretim/gercek-zamanli-uretim.xhtml']

    def parse(self, response):
        view_state = response.xpath(
            '//input[@name="javax.faces.ViewState"]/@value').get()
        yield scrapy.FormRequest.from_response(
            response,
            formid='j_idt22',
            formdata={
                'j_idt202': 'j_idt202',
                'j_idt202:date1_input': '19.04.2020',
                'j_idt202:date2_input': '19.04.2020',
                'j_idt202:powerPlant_focus': '',
                'j_idt202:powerPlant_input': '',
                'j_idt202': 'goster:',
                'j_idt202:dt_rppDD': '24:',
                'javax.faces.ViewState': view_state,
            },
            callback=self.after_ok

        )

    def after_ok(self, response):
        with open('saeed.htm', 'wb') as f:
            f.write(response.body)