I am currently trying to find a item in a list, take it's position and find that same position in another list to replace it with the item in the first list.
example:
list_1 = ['a', 'b', 'c', 'a', 'b', 'c' ]
list_2 = ['1', '2', '3', '1', '2', '3']
I would try to find 'a', take it's index, find the index in the second list and replace that item in that index. So the ones become 'a' in list_2
If I understand correctly the desired output would be this: ['a', '2', '3', '1', '2', '3']. So I would code it something like this:
list_1 = ['a', 'b', 'c', 'a', 'b', 'c']
list_2 = ['1', '2', '3', '1', '2', '3']
def replace_symbol(list_1, list_2, symbol):
symbol_to_replace = list_1.index(symbol)
list_2[symbol_to_replace] = symbol
print(list_2) # prints ['a', '2', '3', '1', '2', '3']
return list_2
replace_symbol(list_1, list_2, 'a') # pass the symbol to replace in the function call
You could use list_1.index('a') to get 'a' index if there was only one instance of that letter. But as I might see you have duplicate values in your list so for loop should work for that.
list_1 = ['a', 'b', 'c', 'a', 'b', 'c' ]
list_2 = ['1', '2', '3', '1', '2', '3']
indexes = []
search_value = 'a'
for e, value in enumerate(list_1): # e is basically our counter here so we use it later to find current position index
if value == search_value:
indexes.append(e)
if len(indexes) > 0: # check if our indexes list is not empty
for index in indexes:
list_2[index] = search_value
print(list_2)
Which will result in :
['a', '2', '3', 'a', '2', '3']
Something like this?
def replace_el(l1, l2, el):
try:
l2[l1.index(el)] = el
except ValueError:
pass
list_1 = ['a', 'b', 'c', 'a', 'b', 'c' ]
list_2 = ['1', '2', '3', '1', '2', '3']
replace_el(list_1, list_2, 'k')
print(list_2)
replace_el(list_1, list_2, 'a')
print(list_2)
And this is the output:
['1', '2', '3', '1', '2', '3']
['a', '2', '3', '1', '2', '3']
The function replace_el replaces the element of l2 in the same position of el in l1. If el is not in l1, l2 is unchanged.
You can find the index of any value with <sequence>.index(<value>).
This "index code" finds the desired item in the first list and in list_2 inserts this same item using the index just found:
list_1 = ['b', 'c', 'a', 'b', 'c' ]
list_2 = ['1', '2', '3', '1', '2', '3']
item = 'a'
item_index = list_1.index(item)
list_2.insert(item_index, item)
print(list_1)
print(list_2)
In the example above, the output is this:
['b', 'c', 'a', 'b', 'c']
['1', '2', 'a', '3', '1', '2', '3']
