如何在dplyr 0.7.0中将列名指定为字符元素？

借用：

库（dplyr）
df根据aosmith的链接，我们可以找到lukeA的答案。。。针对该用例修改的是：

library(dplyr)
library(rlang)
df <- data.frame( 
  color = c("blue", "black", "blue", "blue", "black"), 
  value = 1:5)

# In interactive mode
column_name <- rlang::sym("color")
df %>% filter((!!column_name) == "blue")

# In a function
filter_col <- function(df, col_name_as_string, val){
  col_name <- rlang::sym(col_name_as_string)
  df %>% filter((!!col_name) == val)
}
filter_col(df, 'color', 'blue')

库（dplyr）
图书馆（rlang）
df根据aosmith的链接，我们可以找到lukeA的答案。。。针对该用例修改的是：

library(dplyr)
library(rlang)
df <- data.frame( 
  color = c("blue", "black", "blue", "blue", "black"), 
  value = 1:5)

# In interactive mode
column_name <- rlang::sym("color")
df %>% filter((!!column_name) == "blue")

# In a function
filter_col <- function(df, col_name_as_string, val){
  col_name <- rlang::sym(col_name_as_string)
  df %>% filter((!!col_name) == val)
}
filter_col(df, 'color', 'blue')

库（dplyr）
图书馆（rlang）
df您需要rlang提供的
sym
作为字符串变量。请参阅，例如，对于作为字符串的变量，您需要从rlang获得
sym
。参见，例如。，
column_name <- "color"
col_name <- quo(column_name) # <- something else goes here
df %>% filter((!!col_name) == "blue")

library(dplyr)
library(rlang)
df <- data.frame( 
  color = c("blue", "black", "blue", "blue", "black"), 
  value = 1:5)

# In interactive mode
column_name <- rlang::sym("color")
df %>% filter((!!column_name) == "blue")

# In a function
filter_col <- function(df, col_name_as_string, val){
  col_name <- rlang::sym(col_name_as_string)
  df %>% filter((!!col_name) == val)
}
filter_col(df, 'color', 'blue')