无法使用 Sys.sleep() 解决 HTTP 错误 429

Question

我尝试了这段代码，但服务器向我发回了 HTTP 429 错误，因为请求太多。如果我为每个汽车属性创建一个 function ，代码就会运行，但我希望它们分开，因为为了在我的分析中进一步移动，我将运行 radnom森林和回归树。请注意，即使有时间睡眠，代码也不会运行。

library("robotstxt")
library("dplyr")
library("rvest")

###### Empty Data frame
CARS<-data.frame()

for (page_result in seq(from=1, to=2710)) {
  link<-paste0("https://www.car.gr/classifieds/cars/?fs=1&condition=used&offer_type=sale&significant_damage=f&modified=15&pg=",
               page_result)
  
  page<-curl::curl(link) %>% read_html(link)
  
  sleep_list<-c(8,10,7)                                                            ##########Delay the code 
  i<-sample(sleep_list,1)
  Sys.sleep(i)
  name<-read_html(link)
  Sys.sleep(i)
  Title<-page %>% html_nodes(".title") %>% html_text2()                                      #####Web scrap for the names
  Sys.sleep(i)
  Price<-page %>% html_nodes(".price-fmt") %>% html_text2()                                  #####Web scrap for the prices    
  Sys.sleep(i)
  car_links<-page %>% html_nodes(".row-anchor") %>% 
    html_attr("href") %>% paste0("https://www.car.gr", .)                                    #######extract the links of each car to scrap     
  Sys.sleep(i)
  color<-sapply(car_links,get_color,simplify = TRUE)
  Sys.sleep(i)
  gearing_system<-sapply(car_links,get_gearing_sys)
  Sys.sleep(i)
  HP<-sapply(car_links,get_car_HP,simplify = TRUE)
  Sys.sleep(i)
  CC<-sapply(car_links,get_car_CC,simplify = TRUE)
  Sys.sleep(i)
  FUEL<-sapply(car_links,get_car_fuel,simplify = TRUE)
  Sys.sleep(i)
  KM<-sapply(car_links,get_car_km,simplify = TRUE)
  Sys.sleep(i)
  DATE<-sapply(car_links,get_car_km,simplify = TRUE)
  Sys.sleep(i)
  CATEGORY<-sapply(car_links,get_car_category,simplify = TRUE) 
  Sys.sleep(i)
  SELLER<-SAPPLY(car_links,get_seller,simplify = TRUE)
  CARS <- rbind(CARS,data.frame(Title,Price,color,gearing_system,HP,CC,FUEL,KM,DATE,SELLER,stringsAsFactors = FALSE))
  
  print(paste("Page", page_result,"of","2710"))
}

######## Functions for getting each single attributes in one single scrap

get_seller<- function(car_link){  
  car_page<-read_html(car_link)
  car_page<-read_html(link) %>% html_node(".tw-my-2:nth-child(11) .tw-text-xl") %>% html_text2()
  return(SELLER)
}

get_color<-function(car_link){
  car_page<-read_html(car_link)
  car_color<-car_page %>% html_node("tr:nth-child(12) span") %>% html_text2()
  return(car_color)
}

get_gearing_sys<-function(car_link){
  car_page<-read_html(car_link)
  car_gearing_sys<-car_page %>% html_node("tr:nth-child(11) span") %>% html_text2()
  return(car_gearing_sys)
}

get_car_HP<-function(car_link){
  car_page<-read_html(car_link)
  car_HP<-car_page %>% html_node("tr:nth-child(10) span") %>% html_text2()
  return(car_HP)
}

get_car_CC<- function(car_link){
  car_page<-read_html(car_link)
  car_CC<- car_page %>% html_node("tr:nth-child(9) span") %>% html_text2()
  return(car_CC)
}

get_car_fuel<- function(car_link){
  car_page<-read_html(car_link)
  car_fuel<-car_page %>% html_node("tr:nth-child(8) span") %>% html_text2()
  return(car_fuel)
}

get_car_km<- function(car_link){
  car_page<-read_html(car_link)
  car_km<- car_page %>% html_node("tr:nth-child(7) span") %>% html_text2()
  return(car_km)
}

get_car_date<-function(car_link){
  car_page<-read_html(car_link)
  car_date<- car_page %>% html_node("tr:nth-child(6) span") %>% html_text2()
  return(car_date)
}

get_car_category<- function(car_link){
  car_page<-read_html(car_link)
  car_category<-car_page %>% html_node(".tw-col-span-6:nth-child(6)") %>% html_text2()
  return(car_category)
}