First occurance of a number in python list

I am new to python so please sorry if it is really very silly kind of question.

I have a long list which consist of two fixed possible numbers (0 and 1).

 e.g: 
 list = [0,0,0,0,0,1,1,1,1,1,1,1]

I don't know which number occurs first in the list but i am sure that if 0 is occuring first in the list than it will consecutive occurance follwing by 1, same case for 1.

I am performing some kind of action on basis of these number conditions (0,1) but also i need to show a msg before first occurance of 0 and 1.

First occurance of first number (in this case 0), i have managed like this.

if list[0] == 0:
   print ('first occurance of 0')
elif list[0] == 1:
   print ('first occurance of 1')

I am not sure how to point out first occurance of 1 during execution of this list.

For this example list i need result like this.

 msg before first occurance of 0
 0
 0
 0
 0
 0
 msg before first occurance of 1
 1
 1
 1
 1
 1
 1
 1 

Solution 1:

Use index to find the first occurrence of an item in a list

>>> l = [0,0,0,0,0,1,1,1,1,1,1,1]
>>> l.index(0)
0
>>> l.index(1)
5

Solution 2:

A solution that works for more than just 0 and 1 can be based to a set containing the elements we encountered so far:

l = [0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1]
s = set()
for x in l:
    if x not in s:
        print("first occurrence of %s" % x)
        s.add(x)
    print(x)

Result:

first occurrence of 0
0
0
0
0
0
first occurrence of 1
1
1
1
1
1
1
1