Python - make your own class attributes iterable

# It can be useful to iterate through data contained 
# in your own custom objects. 
 
# Lets say you have your own class 
class ExampleClass(object):
    def __init__(self):
        self.objectList = []
        self.objectDict = {}
        self.maxItem = 100
        self.objectItem = "" 
    def iterateList(self):
        return self.objectList
    def addListItem(self, item):
        self.objectList.append(item)
    def addDictItem(self, item, value):
        self.objectDict[item] = value
 
 
# create an instance of the class 
# and lets use it's iterating methods 
ec = ExampleClass()
 
# add some example data 
for i in xrange(10):
    ec.addListItem(i)
    ec.addDictItem(i, str(i)+"'s value")
 
# now that we have data lets iterate 
# through the data 
for item in ec.iterateList():
    print item
 
#output: 
#    0 
#    1 
#    2 
#    3 
#    4 
#    5 
#    6 
#    7 
#    8 
#    9 
 
 
 

python dict

# a dictionary is created with curly braces {}

>>> d = {}

>>> type(d)

# add key,value pairs to the dict

>>> d['adam'] = 123422

>>> d['barry'] = 234223

>>> d['charlie'] = 999322

>>> d

{'barry': 234223, 'adam': 123422, 'charlie': 999322}

# test whether keys are in a dict

>>> 'steve' in d

False

>>> 'barry' in d

True

# iterate through a dict's keys

>>> for k in d.iterkeys():

... print k

...

barry

adam

charlie

# get a key's value from the dict

>>> d.get(k)

999322

# iterate through keys and print out key, value

>>> for k in d.iterkeys():

... print k, " = ", d.get(k)

...

barry = 234223

adam = 123422

charlie = 999322

# more detailed info on python dict: http://docs.python.org/library/stdtypes.html#mapping-types-dict