hw1.py

def force_float(str):
    try:
        return float(str)
    except (ValueError):
        return 0.0

def rcp_poll_data(xml):  
    dom = web.Element(test_xml)
    dates = [date.content for date in dom('series value')]
    titles = {}
    for value in dom('graphs graph value'):
        col = value.parent.attributes['title']
        if not col in titles: titles[col] = []
        titles[col].append(force_float(value.content))
    
    titles['date'] = pd.to_datetime(dates)
    return pd.DataFrame(titles).sort('date')

print rcp_poll_data(test_xml)