Andrew Carson Andrew Carson - 2 months ago 16
R Question

How to read a commented out HTML table using readHTMLTable in R

In the past, I have been able to use readHTMLTable in R to pull some football stats. When trying to do so again this year, the tables aren't showing up, even though they are visible on the webpage. Here is an example: http://www.pro-football-reference.com/boxscores/201609080den.htm

When I view the source for the page, the tables are all commented out (which I suspect is why readHTMLTable didn't find them).

Example: search for "team_stats" in source code...

<!--
<div class="table_outer_container">
<div class="overthrow table_container" id="div_team_stats">
<table class="stats_table" id="team_stats" data-cols-to- freeze=1><caption>Team Stats Table</caption>


Questions:

How can the table be commented out in the source yet display in the browser?

Is there a way to read the commented out tables using readHTMLTable (or some other method)?

Answer

You can, in fact, grab it if you use the XPath comment() selector:

library(rvest)

url <- 'http://www.pro-football-reference.com/boxscores/201609080den.htm'

url %>% read_html() %>%                   # parse html
    html_nodes('#all_team_stats') %>%     # select node with comment
    html_nodes(xpath = 'comment()') %>%   # select comments within node
    html_text() %>%                       # return contents as text
    read_html() %>%                       # parse text as html
    html_node('table') %>%                # select table node
    html_table()                          # parse table and return data.frame

##                                 CAR           DEN
## 1         First Downs            21            21
## 2        Rush-Yds-TDs      32-157-1      29-148-2
## 3   Cmp-Att-Yd-TD-INT 18-33-194-1-1 18-26-178-1-2
## 4        Sacked-Yards          3-18          2-19
## 5      Net Pass Yards           176           159
## 6         Total Yards           333           307
## 7        Fumbles-Lost           0-0           1-1
## 8           Turnovers             1             3
## 9     Penalties-Yards          8-85          4-22
## 10   Third Down Conv.          9-15          5-10
## 11  Fourth Down Conv.           0-0           1-1
## 12 Time of Possession         32:19         27:41
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