I want to be able to rename variables using a string such as df %>% rename(string_var) with something like string_var = "A=B".
Many similar questions, none quite apply or refer to deprecated dplyr.
Starting with a dataframe like
df = data.frame(
A=1:4,
B=5:8
)
I can filter using a string variable as the condition:
s = "A<4 & B>5"
by
> df %>% filter(!!rlang::parse_expr(s))
A B
1 2 6
2 3 7
or
> df %>% filter(eval(str2expression(s)))
A B
1 2 6
2 3 7
I can't figure out how to do the same with rename.
> s = "D=A"
> df %>% rename(!!rlang::parse_expr(s))
Error: object 'A' not found
> df %>% rename(eval(str2expression(s)))
Error: object 'A' not found
I also tried
> l = list(D="A")
> l
$D
[1] "A"
> df %>% rename(l)
Note: Using an external vector in selections is ambiguous.
i Use `all_of(l)` instead of `l` to silence this message.
i See <https://tidyselect.r-lib.org/reference/faq-external-vector.html>.
This message is displayed once per session.
Error: Must rename columns with a valid subscript vector.
x Subscript has the wrong type `list`.
i It must be numeric or character.
Run `rlang::last_error()` to see where the error occurred.
> df %>% rename(!!l)
Error: Must rename columns with a valid subscript vector.
x Subscript has the wrong type `list`.
i It must be numeric or character.
Run `rlang::last_error()` to see where the error occurred.