Understanding multiplication syntax with Lists
Question:
I understand the below list concatenation:
r = [1, 2] + [False]
# Output: r = [1, 2, False]
However, I am not able to understand the below syntax:
r = [1, 2][False]
# Output: 1
Answers:
You’re defining an unnamed list, then indexing it with False. Because False has a numeric value of zero (bool is actually a subclass of int, where False has a value 0, and True has a value 1), that’s equivalent to indexing it as index 0, so it’s like you wrote:
__unnamed = [1, 2]
r = __unnamed[0]
I understand the below list concatenation:
r = [1, 2] + [False]
# Output: r = [1, 2, False]
However, I am not able to understand the below syntax:
r = [1, 2][False]
# Output: 1
You’re defining an unnamed list, then indexing it with False. Because False has a numeric value of zero (bool is actually a subclass of int, where False has a value 0, and True has a value 1), that’s equivalent to indexing it as index 0, so it’s like you wrote:
__unnamed = [1, 2]
r = __unnamed[0]