将数据框列粘贴到预先格式化的字符串中

Question

我有一个数据帧，看起来像这样：

df <- tibble::tribble(
                                                  ~topic,   ~substance,
                                  "Pregnancy, High-Risk",  "Krill oil",
        "Pregnancy Complications/ prevention & control*", "Fish oils*",
                "Premature Birth/ prevention & control*",    "Omega 3")

我想将列的每个元素组合成一个预格式化的字符串，表示将在PubMed (一个科学文献数据库)中使用的查询。

查询包含OR、and和AND括号的组合，格式如下：

query <- "((Topic 1) OR (Topic 2) OR (Topic 3)) AND ((Substance 1) OR (Substance 2) OR (Substance 3))"

又名：

(
(Pregnancy, High-Risk)
OR
(Pregnancy Complications/ prevention & control*)
OR
(Premature Birth/ prevention & control*)
)
AND
(
(Krill oil)
OR
(Fish oils*)
OR
(Omega 3)
)

我如何才能以一种面向整洁的方式实现这一点呢？

Answer 1

我认为你可以使用paste在base R中实现这一点。

paste(sapply(df, function(x) 
      paste("(", paste("(", x, ")", collapse = " OR"), ")")), collapse = " AND ")

#"( ( Pregnancy, High-Risk ) OR( Pregnancy Complications/ prevention & control* ) 
#        OR( Premature Birth/ prevention & control* ) ) AND
#     ( ( Krill oil ) OR( Fish oils* ) OR( Omega 3 ) )"

如果有多个列需要联接，则使用sapply。如果你真的需要它，你绝对可以用stringr::str_c来翻译它。