python sort tuple

Some example for sort tuple are given

a=[(1,"b"),(2,"a"),(1,"e")]
print a
print sorted(a)

def myTSort(d):
    return d[0] # sort according to first value

print sorted(a,key=myTSort)
print sorted(a,key=myTSort, reverse=True)
print a

Output:

[(1, 'b'), (2, 'a'), (1, 'e')]
[(1, 'b'), (1, 'e'), (2, 'a')]
[(1, 'b'), (1, 'e'), (2, 'a')]
[(2, 'a'), (1, 'b'), (1, 'e')]
[(1, 'b'), (2, 'a'), (1, 'e')]