type() function and comparison.

Question

to check whether some data were lists or not, --

First, I did this,
>>> a = [1,2,3]
>>> type(a) == 'list'
False

I thought it would return True. But no! So I found an alternative,

>>> str(type(a)) == "<class 'list'>"
True

So, it returned True, luckily.

My question is, why didn't my first method work? 🙁 (I thought it would) and is there some other ways (you know) to perform that same comparison?

Answer 1

You are not comparing like items, it may appear that way, but they are different.

a = [1,2,3] #list instantiated
print(type(a) == 'list') #list being compared to a string
print(type(a) == list) #list being compared to list
print(str(type(a)) == "<class 'list'>") #string being compared to string
print(list) #list class

Answer 2

Don't use string for comparison:
print(type(a) == list) # true

Or if you wanna use a string then you can use the name magic method to get the actual name and not the class:
print(type(a).__name__ == "list") # true

Answer 3

In first method, 'list' is a string, not type..

Answer 4

type(<identifier>) is <typename>

type(a) is list # True

Answer 5

type(a)( ) == [ ] # True

Answer 6

Vitaly Sokol
hey, thanks for you help ☺
but can you please explain,

>>> a = [1,2,4]
>>> type(a)()
[]

why did that happen? 🤔

Answer 7

M Tamim There 'a' is list.
And type(a) return list
then list() creates empty list which is output : []

Answer 8

Jayakrishna🇮🇳
Oh, yeah! thanks, mate, I got it. 😊

Answer 9

Isinstance(a,list)