optionLoop

Simple loop structure to iterate over all combinations of an initializing dictionary

No longer will you need a million nested for-loops…

The optionloop works as follows:

First, initialize a dictionary with various keys and values, e.g.:

d = {'doThingX' : [True, False], 'doThingY' : False,
        'thingZValue' : ['a', 'b', 1]}

Next create the option loop:

oploop = optionloop(d)

Finally iterate and get your values:

for state in oploop:
    doX = state['doThingX']
    doY = state['doThingY']
    zVal = state['thingZValue']

    f(doX, doY, zVal)

This is intended to replace an equivalent looping structure of:

for doX in doThingX:
    for doY in doThingY:
        for zVal in thingZValue:
            f(doX, doY, zVal)

which quickly becomes cumbersome.

Also, option loops can be added to create even more complex looping structures, e.g.:

d1 = {'lang' : ['c'], 'doThingX' : [True, False]}
d2 = {'lang' : ['fortran'], 'doThingX' : [True, False], 'doThingY' : [True, False]}

oploop1 = optionloop(d1)
oploop2 = optionloop(d2)
oploop = oploop1 + oploop2

for state in oploop:
    ...

is equivalent to:

langs = ['c', 'fortran']
doThingX = [True, False]
doThingY = [True, False]

for lang in langs:
    if lang == 'c':
        for doX in doThingX:
            f(lang, doX)
    elif lang == 'fortran':
        for doX in doThingX:
            for doY in doThingY:
                f(lang, doX, doY)

Note, if the order of iteration matters an ordered dict can be used, e.g.:

d = OrderedDict()
d['a'] = [False, True]
d['b'] = [False]
d['c'] = [1, 2, 3]
oploop = optionloop(d)
for state in oploop:
    ...

is equivalent to:

for a in [False, True]:
    for b in [False]:
        for c in [1, 2, 3]:
            ....

Additionally, an option loop (or combination thereof) can be reset using the copy interface:

d1 = {'lang' : ['c'], 'doThingX' : [True, False]}
oploop1 = optionloop(d1)

# iterate through 1

oploop2 = oploop1.copy()