CODEWITHSUNDEEP
pythonpython-2.7
manosbar
manosbar

Reputation: 316

Create set of rules with one flag variable

I have a code which goes like this:

flag = 0
if A == 'string1':
    flag = 1
if B == 'string2':
    flag = 1
if C == 'string3':
    flag = 1

Is there a way to create a list of the rules I want to check, check whether at least one is true, and set flag to 1? For example,

D = [A == 'string1', B == 'string2', C=='string3']
if D:
    flag = 1

Upvotes: 0

Views: 15010

Answers (3)

LVFToENlCx
LVFToENlCx

Reputation: 875

You were almost there. 

D = [A == 'string1', B == 'string2', C=='string3']
if True in D:
    flag = 1

D has the boolean values of each test, True in D tests if any of them are True.

Edit: I wrote this over a year ago, but someone upvoted it recently, and looking back at it, I now know there is a built in that saves a few keystrokes.

We can write the code above as

D = [A == 'string1', B == 'string2', C=='string3']
if any(D):
    flag = 1

Upvotes: 2

Prune
Prune

Reputation: 77837

if A == 'string1' or \
   B == 'string2' or \
   C == 'string3':
    flag = True    # use Boolean values, not coded numbers

Or simply assign the result of the Boolean expression:

flag = A == 'string1' or \
       B == 'string2' or \
       C == 'string3'

This last one will give flag the proper value, either True or False.

If you need a list of variables and values, try something like this:

vars = [A, B, C]
vals = ['string1', 'string2', 'string3']
flag = any([vars[i] == vals[i] for i in range(len(vars)) ])

... or make a dictionary of those same items (courtesy of codehearts):

checks = { 'string1': A, 'string2': B, 'string3': C }
flag = any([var == val for var, val in checks.iteritems() ])

... or zip the list into pairs (tuples) per wwii:

flag = any(a == b for a, b in zip(vars, vals))

You can extend the list sizes as far as you want. This assumes that each "rule" is simply checking paired values.

Upvotes: 4

Alex Pertsev
Alex Pertsev

Reputation: 948

You can use any:

if any((A == 'string1', B == 'string2', C=='string3')):
    flag = 1

Upvotes: 3

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