Execute a function or return a value if a column in present in a dataframe

The simple use case. For more complex behaviour see switch_pipeline().

Usage

if_col_present(df, col, if_present, if_missing = ~.x)

Arguments

df

a dataframe

col

a column name

if_present

a purrr style function to execute on the dataframe if the column is present (or a plain value)

if_missing

a purrr style function to execute on the dataframe if the column is missing (or a plain value)

Value

either the value of if_present/if_absent or the result of calling if_present/if_absent as functions on df.

Examples

iris %>% if_col_present(Species, ~ .x %>% dplyr::rename(new = Species)) %>%
  colnames()
#> [1] "Sepal.Length" "Sepal.Width"  "Petal.Length" "Petal.Width"  "new"         

# in contrast to `purrr` absolute values are not interpreted as function names  
iris %>% if_col_present(Species2, "Yes", "No")
#> [1] "No"