How To Convert 10 Digits With This Format XXX-XXX-XXXX To US Formal Format That Looks Like (XXX) XXX-XXXX Using Python3 Regex Sub

This is my try, it actually put the first and seconds groups of 3 digits between parenthesis while I only need to put the first group only between parenthesis to meet US phone num

Solution 1:

You may use

re.sub(r'(?<!\S)(\d{3})-', r'(\1) ', phone)

See regex demo

Details

• (?<!\S) - a left-hand whitespace boundary
• (\d{3}) - Capturing group #1: three digits
• - - a hyphen.

The replacement is the Group 1 value inside round brackets and a space after (that will replace the hyphen).

Solution 2:

This result will include the checking part for phone format (it must be XXX-XXX-XXXX), if it correct the re.sub function will pass:

import re
def convert_phone_number(phone):
  result = re.sub(r'(?<!\S)(\d{3})-(\d{3})-(\d{4}\b)', r'(\1) \2-\3', phone)
  return result

print(convert_phone_number("My number is 212-345-9999.")) # My number is (212) 345-9999.
print(convert_phone_number("Please call 888-555-1234")) # Please call (888) 555-1234
print(convert_phone_number("123-123-12345")) # 123-123-12345
print(convert_phone_number("Phone number of Buckingham Palace is +44 303 123 7300")) # Phone number of Buckingham Palace is +44 303 123 7300

Solution 3:

re.sub(r"\b\s(\d{3})-", r" (\1) ", phone)

Solution 4:

import re
def convert_phone_number(phone):
  result = re.sub(r"\b\s(\d{3})-\b", r" (\1) ", phone)
  return result

Solution 5:

import re
def convert_phone_number(phone):
  result = re.sub(r" (\d{3})-",r" (\1) ",phone)
  return result