我如何full_join数据帧列表列表 [英] How can I full_join list list of list of dataframes

问题描述

我从一个站点读取了多个URL，现在有一个数据帧列表(tbl)的列表.现在，我需要将这些数据帧列表全部_加入一个数据帧中.

I read multiple urls from a site and now have a list of list of data frames (tbl). Now I need to full_join these lists of data frames into one data frame.

library(xml2)
library(dplyr)
#> 
#> Attaching package: 'dplyr'
#> The following objects are masked from 'package:stats':
#> 
#>     filter, lag
#> The following objects are masked from 'package:base':
#> 
#>     intersect, setdiff, setequal, union
library(purrr)
library(rvest)
#> 
#> Attaching package: 'rvest'
#> The following object is masked from 'package:purrr':
#> 
#>     pluck


url <- file.path(str_c("https://amx.am/en/9/trading/10/instruments", '?page=', 1:3))
#> Error in str_c("https://amx.am/en/9/trading/10/instruments", "?page=", : could not find function "str_c"

tbl <- lapply(url, read_html) %>% lapply(html_table)
#> Error in UseMethod("read_xml"): no applicable method for 'read_xml' applied to an object of class "name"

^{由 reprex软件包(v0.3.0)于2020-01-25创建}

^{Created on 2020-01-25 by the reprex package (v0.3.0)}

推荐答案

每个url中都有多个表，因此可以将它们组合在一起

Each url has multiple tables in them so to combine them together you can use

library(rvest)
library(purrr)
library(dplyr)

map(url, ~read_html(.x) %>% html_table) %>%
   flatten() %>%
   bind_rows()

---

或者如果您想将它们一起full_join，我们可以使用reduce

---

Or if you want to full_join them together, we can do that with reduce

map(url, ~read_html(.x) %>% html_table) %>%
  flatten() %>%
  reduce(full_join))

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