Item — HN Reader

It’s unclear what the big advantage is over `print("Age: "+age)`. It’s even more characters, in that specific example.

3 comments

  >>> age = 32
  >>> print("Age: " + age)
  Traceback (most recent call last):
    File "<stdin>", line 1, in <module>
  TypeError: can only concatenate str (not "int") to str

  >>> print("Age: " + str(age))
  Age: 32

As a side note, I always found it amusing that Python is dynamic but doesn't let you do this, while C# has static typing but lets you do string + number. (I looked into it a while back, I think it's because both are Object, so it does operator overloading on Object+Object and then checks the types...)

Toy examples aren’t the use case, rather multiple variables or expressions, perhaps with formatting (padding) as well.

f-string is shorter, less err prone, and faster for medium complexity or above.

If age is a number, that won’t work.

Admittedly I’m not so familiar with Python; it does work in Java. In that case, introducing a less hazardous string concatenation operator would seem more universally useful.

In Python, that less hazardous string concatenation operator is an f-string.

I’m assuming you can only use it with string literals, hence it is less universally useful.

Nope, you can put expressions in them:

f'{a} = {functionThatReturnsAButHasSideEffects()}'