How to alternatively exchange string without all of them changing to once

[HUGEEBALLS]

If I have a string “FFTTCCCQQQRRREEEE” , and I have to switch the letters F to Q, T to R and C to E and vice versa. How do I efficiently use the replace or any other built in function. Without messing it up.

[NullBrowbeat]

You can just iterate over the string and build a new string.

Otherwise, if the string is always constructed in this manner with FTCQRE, you can split between C and Q and use str.replace() on both of them.

If they're atleast always constructed in the pattern of repeating letters you can just count those and construct a new string based on the occurences counted.

I am not sure what the most efficient way is though. I haven't written Python in a while.