I mean if they can see that we type exit and show us this message, why could they not just start the exiting when we type exit?
Because exit might be a variable you use to determine if you should exit. exit() is a function that actually does the exiting.
It’s the difference between pointing at a jogger and saying “run” and actually running after them.
If you have a variable called exit
you've overwritten the function in that scope, and won't be able to execute it.
e.g.
>>> exit=1
>>> exit()
Traceback (most recent call last):
File "", line 1, in
TypeError: 'int' object is not callable
>>>
Guessing at what the programmer wants instead of implementing consistent behaviour is what Javascript does. Do you want Python to become Javascript?
This is the code (Github link):
class Quitter(object):
def __init__(self, name, eof):
self.name = name
self.eof = eof
def __repr__(self):
return 'Use %s() or %s to exit' % (self.name, self.eof)
def __call__(self, code=None):
# Shells like IDLE catch the SystemExit, but listen when their
# stdin wrapper is closed.
try:
sys.stdin.close()
except:
pass
raise SystemExit(code)
What happens is that the python repl calls __repr__
automatically on each variable/statement that you type into the repl (except assignments e.g. x = 1
).
But this basically only happens in the repl. So "executing" only exit
wouldn't work in a python script as it is not calling __repr__
automatically, so better you learn how to do it right than using just exit
in your python scripts and scratching your head why it works in the repl but not in your code.
import gravity; gravity = None
edit: of course there is an xkcd: https://xkcd.com/353/.
Incidentally, for anyone who hasn't typed 'import antigravity' into an interactive Python terminal...you should - as Dr Seuss says, "These things are fun, and fun is good."
I love how it contains exactly one function: from antigravity import geohash
Hell, this is the entire antigravity library:
import webbrowser
import hashlib
webbrowser.open("https://xkcd.com/353/")
def geohash(latitude, longitude, datedow):
'''Compute geohash() using the Munroe algorithm.
>>> geohash(37.421542, -122.085589, b'2005-05-26-10458.68')
37.857713 -122.544543
'''
# https://xkcd.com/426/
h = hashlib.md5(datedow, usedforsecurity=False).hexdigest()
p, q = [('%f' % float.fromhex('0.' + x)) for x in (h[:16], h[16:32])]
print('%d%s %d%s' % (latitude, p[1:], longitude, q[1:]))
He literally gets a 32-bit hash, uses the first half of it as the latitude decimal, and the second half of it as the longitude decimal,
On Sync it works fine. Moreover, it should work on other clients too. You better open a ticket.