Source       Month  Sessions    Bounce Rate     Avg. Session Duration
ABC.com     201501   408        26.47%           0:03:26

def time_convert(x):
    times = x.split(':')
    return (60*int(times[0])+60*int(times[1]))+int(times[2])

df['Avg. Session Duration'] = df['Avg. Session Duration'].apply(time_convert)

> --------------------------------------------------------------------------- AttributeError                            Traceback (most recent call
> last) <ipython-input-53-01e79de1cb39> in <module>()
> ----> 1 df['Avg. Session Duration'] = df['Avg. Session Duration'].apply(lambda x: x.split(':'))
>
> /Users/yumiyang/anaconda/lib/python2.7/site-packages/pandas/core/series.pyc
> in apply(self, func, convert_dtype, args, **kwds)    1991
> values = lib.map_infer(values, lib.Timestamp)    1992
> -> 1993         mapped = lib.map_infer(values, f, convert=convert_dtype)    1994         if len(mapped) and
> isinstance(mapped[0], Series):    1995             from
> pandas.core.frame import DataFrame
>
> /Users/yumiyang/anaconda/lib/python2.7/site-packages/pandas/lib.so in
> pandas.lib.map_infer (pandas/lib.c:52281)()
>
> <ipython-input-53-01e79de1cb39> in <lambda>(x)
> ----> 1 df['Avg. Session Duration'] = df['Avg. Session Duration'].apply(lambda x: x.split(':'))
>
> AttributeError: 'float' object has no attribute 'split'