I'm wondering how to use an f-string whilst using r to get a raw string literal. I currently have it as below but would like the option of allowing any name to replace Alex I was thinking adding an f-string and then replacing Alex with curly braces and putting username inside but this doesn't work with the r.
username = input('Enter name')
download_folder = r'C:\Users\Alex\Downloads'
You can combine the f for an f-string with the r for a raw string:
user = 'Alex'
dirToSee = fr'C:\Users\{user}\Downloads'
print (dirToSee) # prints C:\Users\Alex\Downloads
The r only disables backslash escape sequence processing, not f-string processing.
Quoting the docs:
The 'f' may be combined with 'r', but not with 'b' or 'u', therefore raw formatted strings are possible, but formatted bytes literals are not.
...
Unless an 'r' or 'R' prefix is present, escape sequences in string and bytes literals are interpreted...
Alternatively, you could use the str.format() method.
name = input("What is your name? ")
print(r"C:\Users\{name}\Downloads".format(name=name))
This will format the raw string by inserting the name value.
Raw f-strings are very useful when dealing with dynamic regular expressions. https://www.python.org/dev/peps/pep-0498/#raw-f-strings contains a lot of useful information.
Since you are working with file paths, I would avoid f-strings and rather use a library geared for path manipulation. For example pathlib would allow you to do:
from pathlib import Path
username = input('Enter name')
download_folder = Path('C:/Users', username, 'Downloads')
This approach also offers some other common file operations such as, such as is_dir open.
Alternatively you could also use os.path.join)