Try & Except, correct way

Question

The right way to use the try and except in the Python it’s like?

try:
  variavel = funcao()
except:
  return 'error'

Or do I:

variavel = funcao() and then I’ll deal with it that way

variavel = funcao()

try:
 return variavel
except:
 return 'error'

Whatever? I’m a beginner in Python, and in PHP I’ve never used try and catch

Answer 1

First thing is to never use one except with nothing - in Python 3 (which is what you should be using - Python 2 is incompatible and is a language at the line-out limit -use Python 3), empty "except" is syntax error.

Even the except Exception - which is an exception that 'grabs all' should be avoided, unless the error handling block includes a way to log the error for further analysis.

The correct form is: have as little code as possible inside the block try, and have the most specific exceptions possible in Except. The idea is never to "pretend you didn’t see the error" - but rather, to prevent the program from halting in a situation that was already predicted and does not depend on the program: a network timeout, an unavailable response from a server, a write-protected file, an account made with numbers provided by the user that arrives in a division by zero, etc...

And finally, as to your specific question - there is no so much importance so, but it is better you keep less points return inside a function, why it is easier to understand what is happening to debug and give maintenance -

then:

try:
    resultado = funcao()
except ValueError:
    resultado = "erro"

return resultado

Note how the ideal is to have specific exceptions- if within the function end the available memory for the process, this gives a MemoryError and the program to. When the program stops, the traceback will tell you where the error occurred, and just go there and fix the stretch that is creating an object larger than is possible. If it were a Except generic, the developer would think it was a ValueError, that could happen anyway, and would stay hours on top of that trying to find the problem.