dplyr 0.7等效于不推荐使用的mutate_ [英] dplyr 0.7 equivalent for deprecated mutate_

问题描述

我在dplyr 0.7中找不到替换将要弃用的 mutate _ 函数的方法.

I cannot find in dplyr 0.7 a way to replace the mutate_ function which is going to be deprecated.

在我的用例中， mutate _ 函数很有用:我在数据库(字符串格式)中存储了许多指令(可以根据需要进行过滤)，并将这些指令应用于一个或几个数据帧.

The mutate_ function is useful in my use case : I store in a database (string format) many instructions (that can be filtered if needed) and apply these instructions to one or several data frames.

例如:

dplyr::tibble(test = "test@test") %>% 
  dplyr::mutate_(.dots = list("test2" = "substr(test, 1, 5)",
                              "test3" = "substr(test, 5, 5)"))

使用dplyr 0.7可以将变量和指令保留为字符吗?

Is there a way to do this with dplyr 0.7 keeping variables and instructions as character?

推荐答案

在 MrFlick 的基础上进行扩展例如，假设您有许多以字符串形式存储的指令，以及要分配给结果计算的相应名称:

To expand a little bit on MrFlick's example, let's assume you have a number of instructions stored as strings, as well as the corresponding names that you want to assign to the resulting computations:

ln <- list( "test2", "test3" )
lf <- list( "substr(test, 1, 5)", "substr(test, 5, 5)" )

将名称与他们的说明相匹配，然后将所有内容转换为quasures:

Match up names to their instructions and convert everything to quosures:

ll <- setNames( lf, ln ) %>% lapply( rlang::parse_quosure )

根据 aosmith 的建议，现在可以使用特殊的!!!将整个列表传递给mutate运算符:

As per aosmith's suggestion, the entire list can now be passed to mutate, using the special !!! operator:

tibble( test = "test@test" ) %>% mutate( !!! ll )
# # A tibble: 1 x 3
#        test test2 test3
#       <chr> <chr> <chr>
# 1 test@test test@     @

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