How can I use try and except to handle bad names?

Question

How can I write the below code, in a way that it only accepts names instead of integers or floats?

try:
    name = input("What is your name?: ")
    print("Your name is " +name)
except:
    print("That isn't a valid name")

Answer 1

Here's an example using exceptions for checking whether given name could be a float or int, and looping until a valid name is given:

# Loop until break out
while True:
    name = input("What is your name?: ")

    try:
        int(name)
        print("An int is not a valid name")
        # Go to start of loop
        continue
    except ValueError:
        # Continue to next check
        pass

    try:
        float(name)
        print("A float is not a valid name")
        # Go to start of loop
        continue
    except ValueError:
        # Break loop if both exceptions are raised
        break

print(f"Hello {name}!")

Answer 2

The Problem Here With Try-Except

If you want to do it using try-except, an approach is to turn the input to an int or a float and then in the except print that the name is valid, like this:

try:
    name = input("What is your name?: ")
    test = float(name)
    print("this is not a valid name")
except:
    print("your name is " + name)

The problem is that the name can be 'foo2' and it still works and to treat exceptions like that you need to write a lot of code.

Isalpha Function

As @JakobSchödl said just use name.isalpha() which return true if the name contains anything that isn't a letter. Implementation below:

name = input("What is your name?: ")
if name.isalpha():
    print("Your name is " +name)
else:
    print("not a valid name")

This is much simpler.

---

Using a Regex

You can also use a regex if you want but it's a bit more complicated, example below.

import re
match = re.match("[A-Z][a-z]+", name)
if match is not None:
    print("your name is " + name)
else:
   print("this is an invalid name")