Python: binary conditions

Question

I have multiple conditions, like this:

if condition:
  flag1 = True
flag2 = testfunc()
flag3 = bool(variable)
if not flag1 and not flag2 and not flag3:
  do0
elif flag1 and flag2:
  do1
elif flag2 and flag3:
  do2

Can I change it to something like this:

flags = 0
if condition:
  flags += 1
if testfunc():
  flags += 2
if bool(variable):
  flags += 4
if flags == 0:
  do0
elif flags == 3:
  do1
elif flags == 6:
  do2

As you can understand there can be values 0, 1, 2, 4, 8, 16, 32, ... for conditions. Is it possible to do something like this in Python? Thanks!

UPDATE. This is something like conditions in re and PyQt4 modules (where you can set something like re.UNICODE | re.DOTALL).

Example from re module:

DOTALL = 16
I = 2
IGNORECASE = 2
L = 4
LOCALE = 4
M = 8
MULTILINE = 8
S = 16
U = 32
UNICODE = 32
VERBOSE = 64
X = 64

Gareth Latty · Accepted Answer · 2012-05-03 22:55:21Z

2

Yes, it's perfectly possible to do this - your code should run fine as is (given variables and functions are declared).

Is it a good idea? Not really - it's much less obvious when reading what you mean. Readability comes first.

If your problem is with the lots of ands, then you can clean it up in other ways:

if not any(condition, flag2, variable):

Using any() and all() can often help you simplify things down.

answered May 3, 2012 at 22:55

Gareth Latty

89.5k18 gold badges184 silver badges187 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

ghostmansd Over a year ago

Wow, it seems to be very useful. I will take it into service!

ghostmansd Over a year ago

However creators of PyQt4 and re are seemed to use the way I ask. Just for education it will be useful to understand how to get something like this. Did they use bits for this?

Gareth Latty Over a year ago

@ghostmansd These are bitwise operators - I would presume that these are used more for consistency with underlying C libraries, and would argue against writing pure-python code that worked in the same way.

Collectives™ on Stack Overflow

Python: binary conditions

1 Answer 1

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related