On Nov 23, 11:19 am, astral orange <457r0...@gmail.com> wrote:
> Hi, I am trying to teach myself Python and have a good book to help me
> but I am stuck on something and I would like for someone to explain
> the following piece of code for me and what it's actually doing.
> Certain parts are very clear but once it enters the "def store(data,
> full_name): ...." function and the "def lookup()..." function things
> get a little confusing for me. Specifically, lines 103-108 *and* Lines
> 110-111.
>
> Lastly, I am not sure how to print the results I've put into this
> program either, the book I'm reading doesn't tell me. As you can tell,
> I am a beginner and I don't truly understand everything that is going
> on here...a lot, but not all....
>
> Here is the code:
>
> 92 def init(data):
> 93 data['first'] = {}
> 94 data['middle'] = {}
> 95 data['last'] = {}
> 96
> 97 def store(data, full_name):
> 98 names = full_name.split()
> 100 if len(names) == 2: names.insert(1, '')
> 101 labels = 'first', 'middle', 'last'
> 103 for label, name in zip(labels, names):
> 104 people = lookup(data, label, name)
> 105 if people:
> 106 people.append(full_name)
> 107 else:
> 108 data[label][name] = [full_name]
> 109
> 110 def lookup(data, label, name):
> 111 return data[label].get(name)
> 112
> 113
> 114 MyNames = {}
> 115 init(MyNames)
> 116 store(MyNames, 'John Larry Smith')
> 117 lookup(MyNames, 'middle', 'Smith')
This is a horrible example to show noobs. I think the OP could better
understand this as a class EVEN though the OP may or may not know what
a class *is* yet.
>>> class Name():
def __init__(self, first, middle, last):
self.first = first
self.middle = middle
self.last = last
>>> name1 = Name('Guido', 'van', 'Rossum')
>>> name1.first
'Guido'
>>> name1.middle
'van'
>>> name1.last
'Rossum'
>>> print name1
<__main__.Name instance at 0x029BFD78>
This time we add a __str__ method, the result will speak louder than
words!!
>>> class Name():
def __init__(self, first, middle, last):
self.first = first
self.middle = middle
self.last = last
def __str__(self):
return '%s %s %s' %(self.first, self.middle, self.last)
>>> name2 = Name('Terry', 'J', 'Reedy')
>>> name2.first
'Terry'
>>> name2.middle
'J'
>>> name2.last
'Reedy'
>>> print name2
Terry J Reedy
See the difference in the print statements. Now lets have some real
fun and access each sub name by index haha!
>>> class Name():
def __init__(self, first, middle, last):
self.first = first
self.middle = middle
self.last = last
def __str__(self):
return '%s %s %s' %(self.first, self.middle, self.last)
def __len__(self):
return 3
def __getitem__(self, item):
if item == 0:
return self.first
elif item == 1:
return self.middle
elif item == 2:
return self.last
else:
raise IndexError("Index must be in range 0, 2")
>>> name = Name('Joe', 'blow', 'scripter')
>>> name[0]
'Joe'
>>> name[1]
'blow'
>>> name[2]
'scripter'
>>> len(name)
3
WOW, thats more info in a few lines than any tut i ever seen! I wish i
could have seen that in my initial days, could have save some
countless hours of confusion!!! Maybe i am in the wrong line of work?
Should i keep going...?
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