Μετατρέψτε την for σε ισοδύναμη while
for i in range(12,10,-1):
print i
i=12
while i>10:
i=i-1
i=i+1
while i<10:
for i in range(20,40,10):
i=20
while i<40
i=i+10
while i<40:
while i>40:
i=10
while i<20:
i=i+40
for i in range(10):
i=0
while i<0:
for i in range(3):
while i<3:
while i>3:
i=3
for i in range(20,40,-10):
i=i-10
for i in range(50,40,10):
i=50