Conditional replace a list element in rstudio

Hello I have a dataframe like the below:

 path.vec                           source.vec                        
1 apple	                            Tuesday	                       
2 lemon	                            Monday	                       
3 orange	                        Wednesday	                       
4c("apple", "lemon", "grape")	    c("Friday", "Monday", "Sunday")     
5c("cheery", "lemon", "grape")	    c("Saturday", "Monday", "Sunday")      
6c("apple", "lemon", "apple")	    c("Thursday", "Monday", "Sunday")   

just 2 variables: path.vec and source.vec. Both are collecting 2 different shadows of the same data

[![enter image description here][1]][1]

I would like simply to swap elements between lists with same index when a condition is met.

Ratio should be:

if df$path.vec contains "apple" swap with df$source.vec same index element

I have tried the below:

df$path.vec <- ifelse(grepl("apple", df$path.vec), df$source.vec, df$path.vec)

but this is changing all the elements, when there is at least one element =="apple", while I want to change just the element "apple". I'm thinking that probably i need to find indexes first and after to base my swap on the index?
I have tried

ind  <- which(df$path.vec %in% c("apple"))

but in my real data set this is an error

Error in `$<`(`*tmp*`, path.index, value = 1:6) : 
 replacement has 6 rows, data has 33422

because it's indexing just when apple is the only element of the list.

I have also tried

df$path.index <- match("apple", df$path.vec)

but this results just in 1 every single row of my dataframe.

Is this one the best way to approach this?

Eventually I would like to obtain another column like the below:                                               
1 Tuesday	                             	                       
2 lemon	                                                     
3 orange	                                            
4c("Friday", "lemon", "grape")	      
5c("cheery", "lemon", "grape")	   
6c("Thursday", "lemon", "Sunday")


My answer would be that you transform your two columns into lists using as.list or similar and then perform grep within a lapply. Here is the code:

path.vec = list("1" = "apple",
                "2" = "lemmon",
                "3" = "orange",
                "4" =c("apple", "lemon", "grape"),
                "5"=c("cheery", "lemon", "grape"),
                "6"=c("apple", "lemon", "apple"))

source.vec = list("1" = "Tuesday",
                  "2" = "Monday",
                  "3" = "Wednesday",
                  "4" = c("Friday", "Monday", "Sunday"),
                  "5" = c("Saturday", "Monday", "Sunday"),
                  "6" = c("Thursday", "Monday", "Sunday")) <- lapply(1:length(path.vec), function(x) {
    res <- path.vec[[x]]
    pos <- grep("apple", res, fixed = T)
    if(length(pos) > 0) res[pos]  <- source.vec[[x]][pos]

Hello Osenam!

thank you very much it worked brilliant.
just for reference, my vectors were already lists but didn't have names, I have added names easily:

names(path.vec) <- c(1:6)


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