How regex a number length 7 in a string but the number is not start with 0 in Python?

Question

I have a string like this:

s = "Abc 3456789 cbd 0045678 def 12345663333"
print(re.findall(r"(?<!d)d{7}(?!d)", s))

Ouput is : 3456789  and 0045678

but I only want to get 3456789. How can I do that?

Answer 1

As per title of finding 7 digit numbers that don't start with 0 you may use:

(?<!d)[1-9]d{6}(?!d)

Note [1-9] at start of match before matching next 6 digits to make it total 7 digits.

RegEx Demo

To make it match any number that doesn't start with 0 use:

(?<!d)[1-9]d*(?!d)