arr = [1, 2, 3, 4, 5]
arr[1:3] = 'ABCD'
arr
[1, 'A', 'B', 'C', 'D', 4, 5]
Exactually, this code is useless. I don't think anyone uses python lists like this. But i wanna know about the result just because of curiosity.
I can know something intuitively seeing result.
old
arr[1:3](2, 3) is gone and replaced by string'ABCD'sequentially.
But just fact about results, I can't understand how it works.
Can I get some hint or docs for understand this result?
Slice assignment takes an iterable on the right-hand. Many things can be iterables, an array or list, for example [8, 9]:
arr = [1, 2, 3, 4, 5]
arr[1:3] = [8, 9]
arr
[1, 8, 9, 4, 5]
A string is an iterable of characters, as you can see in this example
for x in 'ABCD':
print(x)
A
B
C
D
which is why get the result you got. So if what you want is to replace the arr[1:3] slice with a single array element that's a string, you need to give it an iterable that yields that element:
arr = [1, 2, 3, 4, 5]
arr[1:3] = ['ABCD']
arr
[1, 'ABCD', 4, 5]
Note the brackets around the string in the slice assignment statement.