isPhoneNumber.py

#! python
# isPhoneNumber.py
# ATBS: Chapter 7 - Regular expressions exercise

def isPhoneNumber(text):
    if len(text) != 12:
        return False
    for i in range(0, 3):
        if not text[i].isdecimal():
            return False
    if text[3] != '-':
        return False
    for i in range(4, 7):
        if not text[i].isdecimal():
            return False
    if text[7] != '-':
        return False
    for i in range(8, 12):
        if not text[i].isdecimal():
            return False
    return True

print('Is 415-555-4242 a phone number?')
print(isPhoneNumber('415-555-4242'))
print('Is Moshi moshi a phone number?')
print(isPhoneNumber('Moshi moshi'))
message = 'Call me at 415-555-1011 tomorrow.  415-555-9999 is my office.'


for i in range(len(message)):
    chunk = message[i:i+12]
    if isPhoneNumber(chunk):
        print('Phone number found: ' + chunk)
print('Done')