Finding valid phone number

Problem to find the valid phone number.

The valid phone number is

1. The length should be 10.
2. All the character are numbers only.
3. The number start from 6 or 7 or 8 or 9

Example-1:

Input    : n = "9876543210,8976543210,6578994,798790,7986543210,6987543210"
Output   : ['9876543210', '8976543210', '7986543210','6987543210']   

Example-2:

Input    : n = "9#5@6*7&4$,7c8r9a6z5y,8976543210"
Output   : ['8976543210']  

Solution

s = "9876543210,8976543210,6578994,798790,7986543210,5987543210"

result = re.findall(r"[6-7-8-9]{1}[0-9]{9}",s)

print(result)

Output

['9876543210', '8976543210', '7986543210']