python的if语句

a=[2,3,4]
if a[0]>3:
print("this is run")
elif a[2]==4:
print "this is four"
else:
print "no run"

b=(1,2,3,4)
if b[0]>2:
print "this is one step"
else:
print "this is two step"
# output
# this is four
# this is two step