Python(Numpy)- df apply error - IndexError: tuple index out of range
<pre><code>from pandas import DataFrame,Series
import numpy

def avg_bronze_medal():
    countries=['Russian Fed','Norway','Canada']
    gold=[13,11,10]
    silver=[11,5,10]
    bronze=[9,10,5]
    medal_counts={'country_name':Series(countries),'gold':Series(gold),'silver':Series(silver),'bronze':Series(bronze)}
    df=DataFrame(medal_counts)
    print df
    print df['gold'].apply(numpy.mean, axis=1)
</code></pre>

<p>Last line is giving error as "IndexError: tuple index out of range". I need to use apply function in data frame and it should get average of columns gold,bronze and silver. In above example, I used only gold column. Please help me in fixing the error.</p>