Getting a specific details out of a data line using regex and string.replace

I'm supposed to clean up this column called "source" by removing the HTML tags from each source entry. Basically, I only want "Twitter for Iphone" etc. for each item.

I'm also supposed to use trump['source'].str.replace along with a regular expression.

trump['source'] =  ['<a href="" rel="nofollow">Twitter for iPhone</a>',
           '<a href="" rel="nofollow">Twitter for Android</a>',
           '<a href="" rel="nofollow">Twitter Web Client</a>',
           '<a href="" rel="nofollow">Media Studio</a>',
           '<a href="!/download/ipad" rel="nofollow">Twitter for iPad</a>',
           '<a href="" rel="nofollow">Instagram</a>',
           '<a href="" rel="nofollow">Mobile Web (M5)</a>',
           '<a href="" rel="nofollow">Twitter Ads</a>',
           '<a href="" rel="nofollow">Periscope</a>',
           '<a href="" rel="nofollow">Twitter Media Studio</a>']

This is what I have right now but I'm not sure what to do with the string.replace and I'm supposed to use that.

r = r'>(.*)<'

trump['source'] = trump['source'].str.replace(, r)