input: Write a function to search for all indices of elements in a list that match a given search query. Return these indices as a list. If no elements match, return an empty list.
  
  assert search_list(["apple", "banana", "peach", "orange", "grape"], "apple")==[0]
  assert search_list(["apple", "banana", "peach", "orange", "grape"], "orange")==[3]
  assert search_list(["apple", "banana", "peach", "orange", "grape"], "mango")==[]
  assert search_list([], "apple")==[]
output: def search_list(lst, query):
      return [i for i, item in enumerate(lst) if item == query]