使用此代码，您可以获得所需的确切信息:

With this code you get exactly what you're looking for:

subfun0 <- function() {
    e <- parent.frame()
    attr(e, "name") <- "my_env"
    assign("my_env", 1,
                 envir = parent.frame(),
                 inherits = FALSE, immediate = TRUE)
    return(NULL)
}

subsubfun <- function() {
    print("  subsubfun")
    print("  =========")
    print(exists("my_env"))
    print(exists("my_env", parent.frame()))
    print(exists("my_env", parent.frame(2)))
    return(NULL)
}

subfun <- function() {
    print(" subfun")
    print(" ======")
    print(exists("my_env"))
    print(exists("my_env", parent.frame()))
    print(exists("my_env", parent.frame(2)))
    subsubfun()
    return(NULL)
}

fun1 <- function() {
    print("fun1")
    print("====")
    subfun0()
    print(exists("my_env"))
    print(exists("my_env", parent.frame()))
    print(exists("my_env", parent.frame(2)))
    subfun()
    return(NULL)
}

fun1()

[1] "fun1"
[1] "===="
[1] TRUE
[1] FALSE
[1] FALSE
[1] " subfun"
[1] " ======"
[1] FALSE
[1] TRUE
[1] FALSE
[1] "  subsubfun"
[1] "  ========="
[1] FALSE
[1] FALSE
[1] TRUE
NULL

重点在于: parent.frame(2)不等于 parent.env(parent.frame())