Pls someone should volunteer to explain the line three code for me

Question

def f(x):
j = range(x)
e = eval("+".join([str(i * i) for i in j]))
return e
print(f(3))

Answer 1

j=range(3) creates a range object with following values (0, 1,2)

[str(i*i) for i in j] returns ["0", "1", "4"]

join method of string concatenates the values in list with a "+" sign in between each value , i.e. "0+1+4"

eval("0+1+4") evaluates the following expression which returns value 5.

A stackoverflow discussion on how eval works,

https://stackoverflow.com/questions/9383740/what-does-pythons-eval-do#:~:text=10%20Answers&text=The%20eval%20function%20lets%20a%20Python%20program%20run%20Python%20code%20within%20itself.&text=eval()%20interprets%20a%20string%20as%20code.

Answer 2

I don't really see the point of the code unless it's a demonstration of the use of eval(). The square brackets are superfluous and just create more work.

Simpler is

def f(x):
return sum(i**2 for i in range(x))
print(f(3))

https://code.sololearn.com/c7g2P1k404nB