How to find all indices of a certain character in a list or string

Question

For example we have:
alpha = ['a', 'b', 'a', 'c', 'a']
Or
beta = 'abaca'

How can I find all indices of 'a' in alpha and beta?
Is defining a function the only way?

Answer 1

This is a comprehension that can do this taks:

string = 'hello world'
char = 'o'
print([v for v, x in enumerate(string) if x == char])

# result is: [4, 7]

Answer 2

Jan Markus yess thank you so much I guess I should review regular expressions 😅

Answer 3

Steven M thank you very much🙏, pandas seems like a very useful package I should start learning it soon

Answer 4

Could try Pandas?

import pandas as pd

lst=['a','b','a','b','a','b','b','b','a']
df=pd.DataFrame(lst)
print(list(df[df[0]=='a'].index))

Answer 5

Lothar that is a cool method I was also looking for a build in method to this task thank you so much