Transform string to f-string
f-string, python, python-3.x, string-interpolation
Solution
An f-string is syntax, not an object type. You can't convert an arbitrary string to that syntax, the syntax creates a string object, not the other way around.
I'm assuming you want to use `user_input` as a template, so just use the `str.format()` method on the `user_input` object:
variable = 42
user_input = "The answer is {variable}"
formatted = user_input.format(variable=variable)
If you wanted to provide a configurable templating service, create a namespace dictionary with all fields that can be interpolated, and use `str.format()` with the `**kwargs` call syntax to apply the namespace:
namespace = {'foo': 42, 'bar': 'spam, spam, spam, ham and eggs'}
formatted = user_input.format(**namespace)
The user can then use any of the keys in the namespace in `{...}` fields (or none, unused fields are ignored).
Problem
How do I transform a classic string to an f-string? ``` variable = 42 user_input = "The answer is {variable}" print(user_input) ``` Output: `The answer is {variable}` ``` f_user_input = # Here the operation to go from a string to an f-string print(f_user_input) ``` Desired output: `The answer is 42`