Dynamically evaluating simple boolean logic in Python

Posted by a paid nerd on Stack Overflow See other posts from Stack Overflow or by a paid nerd
Published on 2010-03-18T04:49:55Z Indexed on 2010/03/18 4:51 UTC
Read the original article Hit count: 529

Filed under:

python

|

boolean

|

logic

|

boolean-logic

|

tree

I've got some dynamically-generated boolean logic expressions, like:

(A or B) and (C or D)
A or (A and B)
A
empty - evaluates to True

The placeholders get replaced with booleans. Should I,

Convert this information to a Python expression like True or (True or False) and eval it?
Create a binary tree where a node is either a bool or Conjunction/Disjunction object and recursively evaluate it?
Convert it into nested S-expressions and use a Lisp parser?
Something else?

Suggestions welcome.

© Stack Overflow or respective owner

Related posts about python

unmet dependencies in Ubuntu 12.04

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I tried today to install a dvb-card on my Ubuntu 12.04 (Linux blauhai-linux 3.2.0-25-generic #40-Ubuntu SMP Wed May 23 20:30:51 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux ). The installation failed with an error. After that, i tried to install python (it was already installed but i got this error): linux:~$… >>> More
How can I get sikuli-ide to work?

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I installed sikuli-ide with sudo apt-get install sikuli-ide Everything was fine until I tried to start it from the terminal. I typed sikuli-ide But the only response I got was [info] locale: en_US The application was not started, furthermore there is no desktop file and sikuli-ide does not… >>> More
Getting PATH right for python after MacPorts install

as seen on Super User - Search for 'Super User'
I can't import some python libraries (PIL, psycopg2) that I just installed with MacPorts. I looked through these forums, and tried to adjust my PATH variable in $HOME/.bash_profile in order to fix this but it did not work. I added the location of PIL and psycopg2 to PATH. I know that Terminal is… >>> More
call python with system() in R to run a python script emulating the python console

as seen on Stack Overflow - Search for 'Stack Overflow'
I want to pass a chunk of Python code to Python in R with something like system('python ...'), and I'm wondering if there is an easy way to emulate the python console in this case. For example, suppose the code is "print 'hello world'", how can I get the output like this in R? >>> print… >>> More
Python - Calling a non python program from python?

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi, I am currently struggling to call a non python program from a python script. I have a ~1000 files that when passed through this C++ program will generate ~1000 outputs. Each output file must have a distinct name. The command I wish to run is of the form: program_name -input -output -o1 -o2… >>> More

Related posts about boolean

Ubuntu Preseed set Norwegian Keyboard?

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
It's been a couple of days now that I am trying to make a fully automated unattended installation. I managed to make it work with Ubuntu/Cobbler and a preseed file, but I cannot set the correct keyboard layout which is Norwegian in this case. I am doing the tests on a virtual machine and when I am… >>> More
boolean in java: what am I doing wrong?

as seen on Stack Overflow - Search for 'Stack Overflow'
Hello, I am trying to make my boolean value work. I am new at programming java so I must be missing something simple. I am trying to make it so that if one of the tire pressures is below 35 or over 45 the system outputs "bad inflation" For class me must use a boolean which is what I tried. I cant… >>> More
W2k8, Sybase Driver, Permissions

as seen on Server Fault - Search for 'Server Fault'
Trying to get a .net (32bit) app running on a Windows 2008 server. My experience in the Windows world is quite limited. Is this related to the Full/Medium trust settings? Have been Googling for quite some time. Appreciate your feedback! Seeing the following error: Required permissions cannot… >>> More
Xuggler errors as soon as you import git

as seen on Stack Overflow - Search for 'Stack Overflow'
I downloaded the Git straight into Eclipse for Xuggler (Here is the git). But as soon as it loads, there are so many errors I don't know what to do. Most of the errors are "cannot be resolved" type errors. Description Resource Path Location Type The import org.junit cannot be resolved AtomicIntegerTest… >>> More
Designing binary operations(AND, OR, NOT) in graphs DB's like neo4j

as seen on Programmers - Search for 'Programmers'
I'm trying to create a recipe website using a graph database, specifically neo4j using spring-data-neo4j, to try and see what can be done in Graph Databases. My model so far is: (Chef)-[HAS_INGREDIENT]->(Ingredient) (Chef)-[HAS_VALUE]->(Value) (Ingredient)-[HAS_INGREDIENT_VALUE]->(Value) (Recipe)-[REQUIRES_INGREDIENT]->(Ingredient) (Recipe)-[REQUIRES_VALUE]->(Value) I… >>> More