Hi,what is the meaning of this phrase

Question

Lists in Python, like most things, do not actually contain the items inside them. Rather, they contain references

Answer 1

Python stores every value somewhere in memory, you don't get to see it.

In lists, but also generally, only the addresses are stored.

Basically when you say:

print(x)

You are saying: Please go to the place with the name (reference) x and return me that value.

This is important, because any object in Python can have several references.

a = [] gives the name a to a list that is newly created

b = a creates no new list, but gives another name b to the very same list a.

So two references point to only one object in computer memory, although it looks like you have two separate lists a and b.

Often mistakes happen, because people add something to their list...

a.append('Whatever')

... and expect that b is still empty.

Now if they write...

print(b)

...the word Whatever is printed.

Because when they appended to a, they also appended to b - because it's the same list in reality.

Answer 2

Python list can store every value.
For example:
A=["NIG",132,132.0,{1,2},{1:2}]
In this list you can see that there is every type of object.