Python!

Python, but this is actually defined and documented behavior.

Edit: to illustrate what I mean:

not() # True

this actually is not () (the lack of space makes it look like a function), () is a tuple, in python an empty collection returns False, this is to make checks simpler. You can type:

if my_list:
  do something

instead of

if len(my_list) > 0:
  do something

not negates it so you get True

str(not()) # 'True'

converts resulting bool type into a string representation

min(str(not())) # 'T'

This might feel odd, but that's also documented. min() not only allows to compare two numbers like it is in most languages, but you can also provide a sequence of values and it will return the smallest one.

String is a sequence of letters.

Letters are comparable according to ASCII (so you can do sorting). In ASCII table capital letters are first, so the 'T' is the smallest value.

ord(min(str(not()))) # 84

this just converts 'T' to Unicode value which is 84

range(ord(min(str(not())))) # range(0, 84)

This creates a sequence of numbers from 0 to 83

sum(range(ord(min(str(not()))))) # 3486

This works like min() except adds up all the numbers in the sequence together, so in our case 0+1+2+3+...+83 = 3486

chr(sum(range(ord(min(str(not())))))) # 'ඞ'

reverse of ord(), converts Unicode value to a character.