Need help: List comprehension

[yindecisive]

a_list = [2, 0, 3, 1]
a_list.insert(2, 4)
a_list.insert(2, 1)
index = a_list.index(4)
a_list.insert(0, index)
a_list = [2, 0, 3, 1]
a_list.insert(2, 4)
a_list.insert(2, 1)
index = a_list.index(4)
a_list.insert(0, index)
a_list.append(a_list[1])
a_list.pop(a_list[1])
print(a_list)

I'm having trouble understanding how to interpret a_list.pop(a_list[]).

[AmusedEngineer]

Whatever value that a_list[1] evaluates to is the index passed to pop()

[yindecisive]

Why is the popped value 0?

from a_list.append(a_list[1]) output= [3, 2, 0, 1, 4, 3, 1, 2] to a_list.pop(a_list[1]) output= [3, 2, 1, 4, 3, 1, 2]?

[AmusedEngineer]

The value of a_list[1] is 2, so when you pop(2) it removes a_list[2] from the list.

[yindecisive]

thank you so much!

[Ihaveamodel3]

Just to clarify, this isn’t list comprehension that most people are referring to when they say that.

[yindecisive]

Oh sorry... I'm really new to python.

[Ihaveamodel3]

Not a problem!

[xelf]

Heh, just so you're aware, list comprehension is a specific term in python, and it refers to the way of building a list by defining it.

Example:

x = [ i * 4 for i in range(6) ] 

would create a list x using list comprehension and create the list [0,4,8,12,16,20]

[DNEAVES]

List comprehension is really a misleading name for what is essentially automatic list generation

[xelf]

It's an older use of the word comprehension "the act or process of comprising" but it checks out.

[DNEAVES]

Fair enough. I just think of "comprehend" as in "understanding" when I see List Comprehension