I'm completely new at coding in general and was just messing around with lists and I was wondering if there was a way to make a loop go through every element of a list and run it independently of one another. I guess an example would be like:
Input:
List1 = [ "a" , "b" , "c" , "d" , "e" ]
Output:
List2 = [ "a123" , "b123" , "c123" , "d123" , "e123" ]
This is what you are looking for:
list2 = [item + '123' for item in list1]
More on list comprehensions here
list2 = [element + '123' for element in list1]
List_One = [ "a" , "b" , "c" , "d" , "e" ]
TrailingNumbers = 3
for index in range(0, len(List_One)):
for num in range(0,TrailingNumbers+1):
List_One[index] = List_One[index] + str(num)
print(List_One)
This will modify the existing List obviously, didn't see the point in creating a new list, but if you do simply do:
List_Two = []
...
List_Two.append(List_One[index] + str(num))
I also assumed that you didn't have a fixed number to add after each letter.
For instance this would be a dynamical way to add numbers after each letter.
List_One = [ "a" , "b" , "c" , "d" , "e" ]
List_Two = []
TrailingNumbers = 3
for obj in List_One:
List_Two.append(obj + ''.join(list(str(num) for num in range(0,TrailingNumbers+1))))
print(List_Two)
This is another way of doing it where you only use one loop to iterate over the first list, adding to a second list with a generator object for adding the numbers to your string.
A better approach to the first solution is to not count the index yourself and let enumerate() do the job for you. A bit quicker and considered "best practice", it goes something like:
List_One = [ "a" , "b" , "c" , "d" , "e" ]
TrailingNumbers = 3
for index, obj in enumerate(List_One):
for num in range(0,TrailingNumbers+1):
List_One[index] = List_One[index] + str(num)
print(List_One)
It will be a bit quicker, but will do the same job.
list() but then again you'd still need the index number for the object you're modifying. This is instead of using .index() each iteration.
enumerate is the idiomatic way to achive this, sudo_O comment is right, using range is frowned upon (as well modifying the list while iterating over it).enumerate() would work and do the job just as good. Seeing how this guy knows little to nothing about Python i simply wrote what enumerate did to better understand why things are happening. Lists are accessed by indexes, enumerate does exactly the above but gives you the index for each iteration. At least this way you'll be able to see what's happening and why it is happening and also how to use the index in order to access the objects you need?enumerate() doesn't get the length of the list before iterating over it tho, if we're picky. enumerate() will simply do a for obj in list: counter += 1 ...A functional way:
List1 = [ "a" , "b" , "c" , "d" , "e" ]
map(lambda x: x+'123',List1)
