Different list-makin in Python: list() vs []

Question

#both structures works well:
print([i for i in range(10)])
print(list(i for i in range(10)))
#BUT........I Have Some Strange Result:
#for both of them input is: 0 1 2 3 4 5 6 7 8 9
print(list(map(int,input().split())))
print([map(int,input().split())])

#So what a difference between them? You may run it here:
https://code.sololearn.com/cjDu75gBAh1K

Answer 1

(i for i in range(10)) is a generator object. Usually, it won't return anything until you "call" the single values with next() or with a for each loop:

a = (i for i in range(10))
print(type(a)) #output: <class 'generator'>
print(next(a)) #output: 0
print(next(a)) #output: 1
print(next(a)) #output: 2

for n in a:
print(n) #output: 3, 4, 5 etc.

If you use list(i for i in range(10)), you force the generator object to generate all values so that they can be put in a list.

So this is actually a relatively complex way to create a list.

[i for i in range(10)] is a list comprehension and is usally considered the "pythonic" way to create a list.

Answer 2

@Julian Second one gives map object, not a list...

Answer 3

dimon2101 yeah but that one wasn't in the question so i didn't think he/she was talking about that

Answer 4

there pretty much isn't really a big differance.

Answer 5

@Anna Thank you for nice answer!!! I feel some confusing...