Why is generator object returned rather than normal tuple

Question

I have the following:

display_width = 400
centered_width = display_width/2
pt1 = (0,0,0)
adjustedPt1 = (x+1 for x in pt1)
print(adjustedPt1)

which returns the generator object:

<generator object <genexpr> at 0x1064c01d0>

If I however, instead use a list:

display_width = 400
centered_width = display_width/2
pt1 = (0,0,0)
adjustedPt1 = [x+1 for x in pt1]
print(adjustedPt1)

it returns: [1,1,1]