What is the point of initializing a variable to store in memory, when you can just return the actual operation itself?

Love that you implicitely checked for a null or empty string rather than the other submissions here just making a call to the Replace(). Makes it extremely clear on what your edge cases are! Nice job!

Good, but instead, why not break this down into one line and wrap the entire statement in the int() method?

Love the use of lambda functionality. This is very fitting for this simply solved problem

I would recommend other solutions. No point in causing a raise in time complexity (hence the loop).
This can be achieved in much much simpler and more readable ways!

This is good for readability. Easy to understand for beginners!