list1 = [6, 8, 5, 6, 1, 2]
print(list1.index(6, 1))

OP is: 3

1. list1 is a list in python
2. Here list methods are taking place
3. But I am confused with the above code

CodePudding user response：

Since Python indexing starts at 0, Python interprets the command as "Get the index of the second occurrence of the element '6' in the list 'list1'." The second 6 in the list has the index of 3, which is why Python outputs 3.

CodePudding user response：

Try to print this and you will understand why you got this 3

print(list1.index(6))

Anyway, here is a summary for what happened. From the code above I can see you have request to look for number six and print it after index 1. However, if you tried to print

print(list1.index(6,0)) 

It will start looking for 6 in the list from index 0 and it will give you 6 at index 0 try to print after index 4 and it will give an error because after index 4 there is no 6 number in the list and you receive this error

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: 6 is not in list

I hope I was able to answer what in your mind. Also try to check this link for more details. https://www.geeksforgeeks.org/python-list-index/

All the best in learning python ;)