how to sort nested list in python

# Python code to sort the tuples using second element  
# of sublist Inplace way to sort using sort() 
def Sort(sub_li): 
  
    # reverse = None (Sorts in Ascending order) 
    # key is set to sort using second element of  
    # sublist lambda has been used 
    sub_li.sort(key = lambda x: x[1]) 
    return sub_li 
  
# Driver Code 
sub_li =[['rishav', 10], ['akash', 5], ['ram', 20], ['gaurav', 15]] 
print(Sort(sub_li))