Scrapy - Multiple resquest by looping JSON file - scrapy

Question

I'm trying to get the latitude and longitude of different cities. The name of cities are stored in a JSON file. Here is my code:
import scrapy
import json
with open('C:/Users/coppe/tutorial/cities.json') as json_file:
cities = json.load(json_file)
class communes_spider(scrapy.Spider):
name = "geo"
start_urls = ['https://www.latlong.net/']
def parse(self, response):
for city in cities:
return scrapy.FormRequest.from_response(response, formdata={'place': city['city']}, callback=self.get_geo)
def get_geo(self, response):
yield {response.css('span.coordinatetxt::text').get()}
The objective is to loop through the JSON file and for each city send a resquest to a form from the url "https://www.latlong.net/". However nothing is prompting from this request. Is this a bad way to make loop ? Should I treat the JSON file inside the class ?
Log:
2019-04-01 16:27:17 [scrapy.utils.log] INFO: Scrapy 1.5.1 started (bot: tutorial)
2019-04-01 16:27:17 [scrapy.utils.log] INFO: Versions: lxml 4.2.5.0, libxml2 2.9.8, cssselect 1.0.3, parsel 1.5.1, w3lib 1.19.0, Twisted 18.9.0, Python 3.7.1 (default, Oct 28 2018, 08:39:03) [MSC v.1912 64 bit (AMD64)], pyOpenSSL 18.0.0 (OpenSSL 1.0.2p 14 Aug 2018), cryptography 2.3.1, Platform Windows-10-10.0.17763-SP0
2019-04-01 16:27:17 [scrapy.crawler] INFO: Overridden settings: {'BOT_NAME': 'tutorial', 'NEWSPIDER_MODULE': 'tutorial.spiders', 'ROBOTSTXT_OBEY': True, 'SPIDER_MODULES': ['tutorial.spiders']}
2019-04-01 16:27:17 [scrapy.middleware] INFO: Enabled extensions:
['scrapy.extensions.corestats.CoreStats',
'scrapy.extensions.telnet.TelnetConsole',
'scrapy.extensions.logstats.LogStats']
2019-04-01 16:27:17 [scrapy.middleware] INFO: Enabled downloader middlewares:
['scrapy.downloadermiddlewares.robotstxt.RobotsTxtMiddleware',
'scrapy.downloadermiddlewares.httpauth.HttpAuthMiddleware',
'scrapy.downloadermiddlewares.downloadtimeout.DownloadTimeoutMiddleware',
'scrapy.downloadermiddlewares.defaultheaders.DefaultHeadersMiddleware',
'scrapy.downloadermiddlewares.useragent.UserAgentMiddleware',
'scrapy.downloadermiddlewares.retry.RetryMiddleware',
'scrapy.downloadermiddlewares.redirect.MetaRefreshMiddleware',
'scrapy.downloadermiddlewares.httpcompression.HttpCompressionMiddleware',
'scrapy.downloadermiddlewares.redirect.RedirectMiddleware',
'scrapy.downloadermiddlewares.cookies.CookiesMiddleware',
'scrapy.downloadermiddlewares.httpproxy.HttpProxyMiddleware',
'scrapy.downloadermiddlewares.stats.DownloaderStats']
2019-04-01 16:27:17 [scrapy.middleware] INFO: Enabled spider middlewares:
['scrapy.spidermiddlewares.httperror.HttpErrorMiddleware',
'scrapy.spidermiddlewares.offsite.OffsiteMiddleware',
'scrapy.spidermiddlewares.referer.RefererMiddleware',
'scrapy.spidermiddlewares.urllength.UrlLengthMiddleware',
'scrapy.spidermiddlewares.depth.DepthMiddleware']
2019-04-01 16:27:17 [scrapy.middleware] INFO: Enabled item pipelines:
[]
2019-04-01 16:27:17 [scrapy.core.engine] INFO: Spider opened
2019-04-01 16:27:17 [scrapy.extensions.logstats] INFO: Crawled 0 pages (at 0 pages/min), scraped 0 items (at 0 items/min)
2019-04-01 16:27:17 [scrapy.extensions.telnet] DEBUG: Telnet console listening on 127.0.0.1:6023
2019-04-01 16:27:18 [scrapy.core.engine] DEBUG: Crawled (200) <GET https://www.latlong.net/robots.txt> (referer: None)
2019-04-01 16:27:18 [scrapy.core.engine] DEBUG: Crawled (200) <GET https://www.latlong.net/> (referer: None)
2019-04-01 16:27:18 [scrapy.core.engine] DEBUG: Crawled (200) <POST https://www.latlong.net/> (referer: https://www.latlong.net/)
2019-04-01 16:27:18 [scrapy.core.scraper] DEBUG: Scraped from <200 https://www.latlong.net/>
{'latlong': '0,0'}
2019-04-01 16:27:18 [scrapy.core.engine] INFO: Closing spider (finished)
2019-04-01 16:27:18 [scrapy.statscollectors] INFO: Dumping Scrapy stats:
{'downloader/request_bytes': 874,
'downloader/request_count': 3,
'downloader/request_method_count/GET': 2,
'downloader/request_method_count/POST': 1,
'downloader/response_bytes': 29252,
'downloader/response_count': 3,
'downloader/response_status_count/200': 3,
'finish_reason': 'finished',
'finish_time': datetime.datetime(2019, 4, 1, 14, 27, 18, 923987),
'item_scraped_count': 1,
'log_count/DEBUG': 5,
'log_count/INFO': 7,
'request_depth_max': 1,
'response_received_count': 3,
'scheduler/dequeued': 2,
'scheduler/dequeued/memory': 2,
'scheduler/enqueued': 2,
'scheduler/enqueued/memory': 2,
'start_time': datetime.datetime(2019, 4, 1, 14, 27, 17, 773592)}
2019-04-01 16:27:18 [scrapy.core.engine] INFO: Spider closed (finished)

Answer 1

Your parse method should be a generator, so you need to use yield instead of return on the for loop, otherwise you'll finish the loop on the first iteration. Furthermore, get_get method is returning a set, but it must return Request, BaseItem, dict or None.
I suggest changing the code as follow:
import scrapy
import json
with open('C:/Users/coppe/tutorial/cities.json') as json_file:
cities = json.load(json_file)
class communes_spider(scrapy.Spider):
name = "geo"
start_urls = ['https://www.latlong.net/']
def parse(self, response):
for city in cities:
yield scrapy.FormRequest.from_response(response, formdata={'place': city['city']}, callback=self.get_geo)
def get_geo(self, response):
yield {'coord': response.css('span.coordinatetxt::text').get()}
https://www.geeksforgeeks.org/use-yield-keyword-instead-return-keyword-python/