butterfly_life_cycle = ["egg", "larva", "pupa", "butterfly"]
print(butterfly_life_cycle.index("egg"))
print(butterfly_life_cycle.index("larva"))
print(butterfly_life_cycle.index("pupa"))
print(butterfly_life_cycle.index("butterfly"))
# output:
# 0
# 1
# 2
# 3
>>> list1 = [[10,13,17],[3,5,1],[13,11,12]]
>>> list1[0][2]
17