python3 f-string 'invalid syntax'

If you faced 'invalid syntax' while using f-strings in python3 then you probably have ancient python version installed. f-strings feature appeared in 3.6 So you have to install a new python to be able to use f-strings in your code: For example, you are in Ubuntu ( or some other deb-based distrib ):

sudo wget https://www.python.org/ftp/python/3.7.4/Python-3.7.4.tgz sudo tar xzf Python-3.7.4.tgz cd Python-3.7.4 sudo ./configure --enable-optimizations sudo make altinstall # not to replace default python