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Python Python Basics (2015) Logic in Python The Exception to the Rule

What does ValueError mean?

Except is a block, what is ValueError? a variable?

For instance:

try:
    count = int(input('give me a number: '))
except ValueError:
    print("That's not a number")

if I change ValueError to valueerror or Valueerror or any other word, it will get error as below:

give me a number: f
Traceback (most recent call last):
  File "exception.py", line 2, in <module>
count = int(input('give me a number: '))
ValueError: invalid literal for int() with base 10: 'f'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "exception.py", line 3, in <module>
except Valueerror:
NameError: name 'Valueerror' is not defined

Thank you in advance.

1 Answer

Steven Parker
Steven Parker
231,269 Points

:point_right: ValueError is a type of exception.

It's the specific type of exception that would occur if the int operation on the previous line fails, so it's what you want your code to react to when it happens.

Just like variable names, exception names are case sensitive (as you discovered).