Python regex for integer?

Question

I\'m learning regex and I would like to use a regular expression in Python to define only integers - whole numbers but not decimals.

I could make one that only allow

Answer 1

You need to anchor the regex at the start and end of the string:

^[0-9]+$

Explanation:

^      # Start of string
[0-9]+ # one or more digits 0-9
$      # End of string