How do comparison operators < and> work with a function as an operand?

Question

Ran into this problem (in Python 2.7.5) with a little typo:

def foo(): return 3
if foo > 8:
    launch_the_nukes()

Dang it, I accidental

Answer 1

Note: this only works in Python 2.x. In Python 3.x, it gives "TypeError: '(comparison operator)' not supported between instances of 'function' and 'int'".

In Python 2.x, functions are more than infinitely large. For example, in Python 2.7.16 (repl.it), type this:

> def func():
...    return 0
...
> print(func)

> int(func)
Traceback (most recent call last):
  File "", line 1, in 
TypeError: int() argument must be a string or a number, not 'function'
> id(func)
IDNUMBER
> x=id(func)
> func func==x
False
> inf=float("inf")
> func

This shows that 'func' is greater than positive infinity in Python 2.x. Try this in Python 3.8.2 (repl.it):

> def func():
...    return 0
...
> func<10
Traceback (most recent call last):
  File "", line 1, in 
TypeError: '<' not supported between instances of 'function' and 'int'

This shows that comparing with a function as an operand is only supported in Python 2.x, and that when comparing a function in Python 2.x, it is greater than Python's infinity. I hope this helped you!