IM尝试从https://aqicn.org/city/kathmandu进行aqi aqi预测表，但它只是在行中返回na值

Question

# Load required packages
library(rvest)
library(dplyr)

# Define the URL
url <- "https://aqicn.org/city/kathmandu"

# Read the HTML content of the page
webpage <- read_html(url)

# Extract AQI forecast table
tables <- webpage %>%
  html_element("div.section-content") %>%
  html_text()

IM使用此代码，但它只是将我返回带有Na值的Tibble，但在网站中实际上没有任何NA值。有人可以帮助我吗？

Answer 1

文档

ime使用api

library(httr); library(jsonlite)

token <- "demo" # your token here
city <- "here" #"@14866"  # City name or code
url <- paste0("https://api.waqi.info/feed/", city,"/")
response <- GET(url, query = list(token = token))
if (http_status(response)$category == "Success") {
  result <- fromJSON(content(response, "text", encoding = "UTF-8"))
} else {
  print(paste("Error:", http_status(response)$message))
}

尽管我发现，如果我使用正确的城市代码

@14866

，但

here

或

shanghai

工作似乎不起作用。

Method2

由于它没有直接与免费的API合作，我必须使用网络中使用的方法

library(httr)
library(jsonlite)

url <- "https://api2.waqi.info/api/feed/@14866/aqi.json"

headers <- c(
  "Accept" = "*/*",
  "Accept-Encoding" = "gzip, deflate, br, zstd",
  "Accept-Language" = "de-DE,de;q=0.9,en-US;q=0.8,en;q=0.7,zh-TW;q=0.6,zh;q=0.5",
  "Content-Type" = "application/x-www-form-urlencoded",
  "Origin" = "https://aqicn.org",
  "Referer" = "https://aqicn.org/",
  "User-Agent" = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/134.0.0.0 Safari/537.36"
)

response <- POST( # Make the POST request
  url = url,
  add_headers(.headers = headers),
  body = list(),
  encode = "form"
)

if (status_code == 200) { # If successful, parse the JSON content
  result2 <- fromJSON(content(response, "text", encoding = "UTF-8"))
} else {
  print("Request failed")
  print(content(response, "text"))
}