Question

The convert_phone_number function checks for a U.S. phone number format: XXX-XXX-XXXX (3 digits followed by a dash, 3 more digits followed by a dash, and 4 digits), and converts it to a more formal format that looks like this: (XXX) XXX-XXXX. Fill in the regular expression to complete this function. 1 4 import re 2 - def convert_phone_number(phone): 3 result = re.sub) return result 5 6 print(convert_phone_number("My number is 212-345-9999.")) # My number is (212) 345-9999. 7 print(convert_phone_number("Please call 888-555-1234")) # Please call (888) 555 - 1234 8 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 Run 9 Reset

Answer 1

The regular expression that goes in the given blank is r"\b(\d{3})-(\d{3})-(\d{4})\b",r"(\1) \2-\3",phone

Code:

import re

def convert_phone_number(phone):
# The pattern r"\b(\d{3})-(\d{3})-(\d{4})\b" checks for 3 digits followed by a dash, followed by 3 more digits and a dash
# followed by 4 digits.
# r"(\1) \2-\3" indicates to enclose the first 3 digits of the above pattern in paranthesis followed by a space,
# followed by the next three digits and a dash which is followed by the remaining four digits.
result = re.sub(r"\b(\d{3})-(\d{3})-(\d{4})\b",r"(\1) \2-\3",phone)
return result

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

Code in the image:

import re def convert_phone_number(phone): # The pattern rib(\d{3})-(16{3})-(\d{4})\b" checks for 3 digits followed by a dash, followed by 3 more digits and a dash # followed by 4 digits. #r"(11) 12-13" indicates to enclose the first 3 digits of the above pattern in paranthesis followed by a space, # followed by the next three digits and a dash which is followed by the remaining four digits. result = re.sub(r"\b(\d{3})-(\d{3})-(\d{4})\b", "(11) 12-13",phone) return result print(convert_phone_number("My number is 212-345-9999.")) print(convert_phone_number("Please call 888-555-1234")) print(convert_phone_number("123-123-12345")) print(convert_phone_number("Phone number of Buckingham Palace is +44 303 123 7300"))

Output:

(base) sunny@a4ron-5tone:-/Desktop$ python code.py My number is (212) 345-9999. Please call (888) 555-1234 123-123-12345 Phone number of Buckingham Palace is +44 303 123 7300

Explanation:

re.sub(r"\b(\d{3})-(\d{3})-(\d{4})\b",r"(\1) \2-\3",phone)

b(\d{3})-(\d{3})-(\d{4})\b matches the pattern starting with 3 digits followed by a dash, three more digits followed by a dash and then four digits.

(\1) \2-\3 this is used to format the contents of the above matched pattern. The first three digits are enclosed within paranthesis followed by a space, the next three digits followed by a dash and the next four digits.

phone is the parameter in which the above pattern has to be checked and formatted.