Why can't i delete all the numbers < 6??

Question

It's removing 1 and 3 but why it's not removing 2 & 5???

As in the given e.g..

a = [1, 2, 3, 5, 6, 7]

for item in a:
if item < 6:
a.remove(item) #why it is not removing item = 2 & 5 ??
print(a)

Answer 1

That's because lists are mutable and Python avoids automatically making object copies where possible.
And for loop is iterating through a list, that gets removed values over time.

You can fix that by changing the line:
for item in a:
To:
for item in a.copy():

Answer 2

Ahh, thanks a laaot mahn..it worked...

But i still can't understand what you're trying to say..can you plz gimme an example?