script.py

from tkinter import *
from scrapy import Spider
from scrapy.http import Request
import requests
from scrapy.crawler import CrawlerProcess
from uuid import uuid4
from scrapy.utils.project import get_project_settings

# import sys
win = Tk()
a1 = Label(win, text='Query').grid(row=0, column=0)
v = StringVar()
a = Entry(win, textvariable=v).grid(row=0, column=1)
def callback():
	settings = get_project_settings()
	class WallsSpider(Spider):
	    name = 'walls'
	    allowed_domains = ['pexels.com']

	    def __init__(self):
		    self.start_urls = ['http://pexels.com/search/' + v.get()]

	    def parse(self, response):
	        urls = response.xpath('//a[@class="js-photo-link photo-item__link"]/@href').extract()
	        absolute_url = [response.urljoin(i) for i in urls]
	        tags = [i.split('-')[-1][:-1] for i in absolute_url]  # main
	        for i in tags:
	        	image_url = 'https://www.pexels.com/photo/'+ str(i) +'/download/'
	        	r = requests.get(image_url)
	        	file_name = str(uuid4()) + '.jpg'
	        	with open(file_name,'wb') as f: 
	        		f.write(r.content)

	        try:
	            next_page_url = response.xpath('//a[@rel="next"]/@href')[0].extract()
	            abs_next_page_url = response.urljoin(next_page_url) # main
	            return Request(abs_next_page_url)
	        except IndexError:
	            pass 

	# Create a process
	process = CrawlerProcess(settings)
	process.crawl(WallsSpider)
	process.start()

b = Button(win, text="Go", width=10, command=callback)
b.grid(row=0, column=2)
win.mainloop()