PYTHON:

I have a numpy array that holds a name and a phone number suchas this one.

import numpy as np import pandas as pd

LIST = np.array([("James", "Kirk", "512-375-5585"), ("Richard","Branson, "1234567890"), ("James", "Bond", "34567")])

Then I stuff it into a data frame by doing this

df = pd.DataFrame(List, columns=('Firstname', 'Lastname','Phone'))

How would I go about changing 10 digit phone numbers such as1234567890 into 123-456-7890 and discarding invalid ones such as34567 so it reflects in the data frame using a regularexpression?

I have tried df.replace but I am getting errors