list sort vs sorted list

Question

Hey, guys!
Found out anouther one tricky stuff in quiz lib and in python indeed.
Look at the following code:

lst = [34,67,45]
print(lst.sort()==sorted(lst))

Right answer is surprisingly False! Surprisingly because if put inplace sort operation before comparision like here:

lst = [34,67,45]
lst.sort()
print(lst==sorted(lst))
https://code.sololearn.com/crzl8w9LBbBd

the output is True!

Does anybode know how it is working? Why lst.sort()==sorted(lst) is False actually?

Answer 1

sort changes the original list by sortsing it but does NOT return a new list

sorted does not change the original list but returns a new sorted list

basically what it translated to is None==sorted(lst) as sort does not returns anything

just try this:

print(lst.sort())
print(sorted(lst))

and post your results here

Answer 2

@sayan chandra

list.sort() works by changing the list object
so no need for it to return anything

same way as if you declare a function that does not return anything and print its output

def foo():
x = 1

print(foo()) # outputs None

Answer 3

sure thing 👍

Answer 4

@Burey

Thank you, for the explaination!👌

Answer 5

It has to do with the return Datatype of the function, whether it is an object or a list.

Answer 6

Burey, thank you for your help!
And you asked :)
None
[34, 45, 67]
I just forgot that inplace method 'sort' actually returns nothing (None).

Answer 7

so...
whats the use of...
list.sort()
it returns none...
how and when we use it then????

Answer 8

burey
..plz tell me...the use...

Answer 9

hmm