R - 为 rvest 创建不同的链接以供使用

Question

我在创建适当的 links 以便稍后用于数据挖掘时遇到了问题。假设 link 应该是这样的： www.domain.com/city/month/week。每个数据（城市、月份等）都是一个向量。城市是字符串，月份和星期是数字 [1:12] 和 [1:5]。我的目标是创建包含城市、月份和周的所有可能组合的 link （例如：

[1] www.domain.com/Denver/1/1, 
[2] www.domain.com/Denver/1/2, 
[3] www.domain.com/Denver/1/3,
........ 
[53] www.domain.com/Denver/10/3
........
[2823]www.domain.com/Phoenix/12/5

等等）

我敢打赌有一个我没有想到的简单解决方案。

提前致谢！

Answer 1

eg <- expand.grid(
  host = "www.domain.com",
  city = c("Denver", "Phoenix"),
  month = 1:2,
  week = 1:3)
eg
#              host    city month week
# 1  www.domain.com  Denver     1    1
# 2  www.domain.com Phoenix     1    1
# 3  www.domain.com  Denver     2    1
# 4  www.domain.com Phoenix     2    1
# 5  www.domain.com  Denver     1    2
# 6  www.domain.com Phoenix     1    2
# 7  www.domain.com  Denver     2    2
# 8  www.domain.com Phoenix     2    2
# 9  www.domain.com  Denver     1    3
# 10 www.domain.com Phoenix     1    3
# 11 www.domain.com  Denver     2    3
# 12 www.domain.com Phoenix     2    3

do.call(paste, c(eg, sep = "/"))
#  [1] "www.domain.com/Denver/1/1"  "www.domain.com/Phoenix/1/1"
#  [3] "www.domain.com/Denver/2/1"  "www.domain.com/Phoenix/2/1"
#  [5] "www.domain.com/Denver/1/2"  "www.domain.com/Phoenix/1/2"
#  [7] "www.domain.com/Denver/2/2"  "www.domain.com/Phoenix/2/2"
#  [9] "www.domain.com/Denver/1/3"  "www.domain.com/Phoenix/1/3"
# [11] "www.domain.com/Denver/2/3"  "www.domain.com/Phoenix/2/3"

R - 为 rvest 创建不同的链接以供使用

R - creating diverse links for rvest to use

r

dplyr

data-mining

rvest

stringi