Μετατρέψτε την for σε ισοδύναμη while
for i in range(3,13):
print i
i=13
while i<3:
i=i+1
i=3
while i<13:
while i>13:
for i in range(20,40,10):
i=20
while i<40:
i=i+10
i=10
while i<20:
i=i+40
while i<40
while i>40:
for i in range(12,10,-1):
i=12
while i>10:
i=i-1
while i<10:
for i in range(20,10,-5):
i=i-5
i=i+5
for i in range(12,13):
while i<12:
for i in range(10):
while i<0:
i=0