XOR in Python, SyntaxError, why?

Question

>>> x = 1101 ^ 0111
  File "<stdin>", line 1
    x = 1101 ^ 0111
                  ^

SyntaxError: invalid token

Why am I getting this syntax error in python? I see online that, "^ Bitwise Exclusive XOR Description Returns the result of bitwise XOR of two integers.

Syntax A ^ B

A Integer object. B Integer object."

So I think I am using two integers.

`0111` is not a valid integer literal. What did you intend to create? — juanpa.arrivillaga, Apr 12 '21 at 00:17

score 3 · Answer 1 · answered Apr 12 '21 at 00:15

3

are 1101 and 0111 supposed to be bits? To represent bit literals, you should use 0b1101 and 0b0111, because otherwise those are integers (and ints can't start with a 0

answered Apr 12 '21 at 00:15

Adam Smith

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Well, they are still `int` objects – juanpa.arrivillaga Apr 12 '21 at 00:17
@juanpa.arrivillaga true, that was a bit imprecise. – Adam Smith Apr 12 '21 at 00:28
1

@AdamSmith I don't know if that pun was intentional but it was hilarious either way! – Jacobjanak Apr 12 '21 at 00:47

score 1 · Answer 2 · answered Apr 12 '21 at 00:22

First, you cannot use integers in such a way. Here is the error I got when I ran your code:

SyntaxError: leading zeros in decimal integer literals are not permitted;
use an 0o prefix for octal integers

In other words, you can't give Python an integer that starts with a zero. That used to work in Python 2 but is no longer supported in Python 3. (see https://stackoverflow.com/a/11620174/7583007)

I am assuming you are trying to use binary numbers? If so, you should try this: https://stackoverflow.com/a/19414115/7583007

You can specify binary literals in Python3 (and Python2) with a leading `0b`. `assert 0b111 == 7` — Adam Smith, Apr 12 '21 at 00:40

score 1 · Answer 3 · answered Apr 12 '21 at 00:29

I believe you wanted:

0b1101 ^ 0b0111

In general, the error you are receiving is because you placed a "0" in front of a number, something that python doesn't allow. The same would happen if you tried to do:

The start of a number beginning with zero, typically is special python code that indicates you will be providing a binary number, octal number, or hexidecimal number, which begin with 0b, 0o, or 0x, respectively.

XOR in Python, SyntaxError, why?

3 Answers3