lst = [1, 2, 3, 4, 5, 6]
for i, item in enumerate(lst):
while i < 3:
print (i, item)
i += 1
print ('---')
for i in range(len(lst)):
while i < 3:
print (i, lst[i])
i += 1
print ('---')
i = 0
while i < len(lst):
while i < 3:
print (i, lst[i])
i += 1
i += 1
bHN0ID0gWzEsIDIsIDMsIDQsIDUsIDZdCmZvciBpLCBpdGVtIGluIGVudW1lcmF0ZShsc3QpOgogICAgd2hpbGUgaSA8IDM6CiAgICAgICAgcHJpbnQgKGksIGl0ZW0pCiAgICAgICAgaSArPSAxCnByaW50ICgnLS0tJykKZm9yIGkgaW4gcmFuZ2UobGVuKGxzdCkpOgogICAgd2hpbGUgaSA8IDM6CiAgICAgICAgcHJpbnQgKGksIGxzdFtpXSkKICAgICAgICBpICs9IDEKcHJpbnQgKCctLS0nKQppID0gMAp3aGlsZSBpIDwgbGVuKGxzdCk6CiAgICB3aGlsZSBpIDwgMzoKICAgICAgICBwcmludCAoaSwgbHN0W2ldKQogICAgICAgIGkgKz0gMQogICAgaSArPSAx
(0, 1)
(1, 1)
(2, 1)
(1, 2)
(2, 2)
(2, 3)
---
(0, 1)
(1, 2)
(2, 3)
(1, 2)
(2, 3)
(2, 3)
---
(0, 1)
(1, 2)
(2, 3)