my list is like this, in example the string is 'a' and 'b' ; i want to return the index of string 'a' and for 'b' then i want to calculate how many time is 'a' repeated in the list1 :
list1=['a','a','b','a','a','b','a','a','b','a','b','a','a']
i want to return the order of evry 'a' in list1 the result should be like this :
a_position=[1,2,4,5,7,8,10,12,13]
and i want to calculate how many time 'a' is repeated in list1:
a_rep=9
You could do below:
a_positions = [idx + 1 for idx, el in enumerate(list1) if el == 'a']
a_repitition = len(a_positions)
print(a_positions):
[1, 2, 4, 5, 7, 8, 10, 12, 13]
print(a_repitition):
9
If you need repititions of each element you can also use collections.Counter
from collections import Counter
counter = Counter(list1)
print(counter['a']):
9
If you want to get the indices and counts of all letters:
list1=['a','a','b','a','a','b','a','a','b','a','b','a','a']
pos = {}
for i,c in enumerate(list1, start=1): # 1-based indexing
pos.setdefault(c, []).append(i)
pos
# {'a': [1, 2, 4, 5, 7, 8, 10, 12, 13],
# 'b': [3, 6, 9, 11]}
counts = {k: len(v) for k,v in pos.items()}
# {'a': 9, 'b': 4}
