<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def get_a(html, find=''):
 """Finds all the 'a' tags with find in their href"""

    links = []
    for a in html.find_all('a'):
        if a.get('href').find(find) != -1:
            links.append(a)
    return links