[Tutor] Dictionary Issue

[Ltc Hotspot]

On Thu, Aug 6, 2015 at 3:00 PM, Alan Gauld <alan.gauld at btinternet.com>
wrote:

> On 06/08/15 19:30, Ltc Hotspot wrote:
>
> I moved counter outside the loop and below dict, maxval = None
>> maxkee = None are both positioned outside the loop.
>>
>
> You moved counter but it is still a dict() and you
> don't use it anywhere.
>
> URL link to the revisions are available at http://tinyurl.com/nvzdw8k
>>
>> Question: How do I define Counter
>>
>
> Counter is defined for you in the collections module.
> So to use it you need to import collections and access it as
> collections.Counter.
>
> But did you read how to use it? It is a lot more than
> just a dictionary, it has many extra methods, some of
> which almost solve your problem for you. (Whether your
> teacher will approve of using Counter is another
> issue!)
>
> Revised code reads:
>> fname = raw_input("Enter file name: ")
>> handle = open (fname, 'r')
>>
>> counter = dict ()
>> c = Counter(['address'])
>>
>
> You only need to pass a list if you are adding multiple things.
>
> But by the same token you can add a list of items, such
> as email addresses. So if you had such a list you could
> create a Counter() to hold them and count them for you.
> And return the one with the highest value.
> Sound familiar?
>
> Please (re)read the Counter documentation.
> Then play with one in the >>> prompt.
> Don't expect us to just provide you with code, learn
> how it works for yourself. Experiment.
>
> The >>> prompt is your friend. You will learn more from that in 15 minutes
> than in a bunch of emails showing other peoples
> code.
>
> Alternatively forget about Counter and just go back to
> your dict(). You have written all the code you need already,
> you just need to assemble it in the correct order.
>
> maxval = None
>> maxkee = None
>>
>> for line in handle:
>>      if line.startswith("From: "):
>>          address = line.split()[1]
>>
>
> You are not storing the addresses anywhere.
>
> for maxkee, val in c.items():
>>
>>          maxval = val
>>          maxkee = kee
>>
>
> You are still not testing if its the maximum,
> you just keep overwriting the variables for
> each element.
>
> print maxkee and maxval
>>
>
> You still have an 'and' in there.
>
> --
> Alan G
> Author of the Learn to Program web site
> http://www.alan-g.me.uk/
> http://www.amazon.com/author/alan_gauld
> Follow my photo-blog on Flickr at:
> http://www.flickr.com/photos/alangauldphotos
>
>
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Hi Alan,

Questions(1):Why does print line, prints blank space; and, (2) print
address prints a single email address:

View print results as follows:

In [70]: %run assignment_9_4_24.py
Enter file name: mbox-short.txt
ray at media.berkeley.edu 1

In [71]: print handle
<open file 'mbox-short.txt', mode 'r' at 0x00000000035576F0>

In [72]: print count
{'gopal.ramasammycook at gmail.com': 1, 'louis at media.berkeley.edu': 3,
'cwen at iupui.
edu': 5, 'antranig at caret.cam.ac.uk': 1, 'rjlowe at iupui.edu': 2,
'gsilver at umich.ed
u': 3, 'david.horwitz at uct.ac.za': 4, 'wagnermr at iupui.edu': 1, '
zqian at umich.edu':
 4, 'stephen.marquard at uct.ac.za': 2, 'ray at media.berkeley.edu': 1}

In [73]: print line


In [74]: print address
cwen at iupui.edu


Question(3): why did the elements print count('keys') and print
count('items') fail?

View print commands as follows:


In [75]: dir (count)
Out[75]:
['__class__',
 '__cmp__',
 '__contains__',
 '__delattr__',
 '__delitem__',
 '__doc__',
 '__eq__',
 '__format__',
 '__ge__',
 '__getattribute__',
 '__getitem__',
 '__gt__',
 '__hash__',
 '__init__',
 '__iter__',
 '__le__',
 '__len__',
 '__lt__',
 '__ne__',
 '__new__',
 '__reduce__',
 '__reduce_ex__',
 '__repr__',
 '__setattr__',
 '__setitem__',
 '__sizeof__',
 '__str__',
 '__subclasshook__',
 'clear',
 'copy',
 'fromkeys',
 'get',
 'has_key',
 'items',
 'iteritems',
 'iterkeys',
 'itervalues',
 'keys',
 'pop',
 'popitem',
 'setdefault',
 'update',
 'values',
 'viewitems',
 'viewkeys',
 'viewvalues']

In [76]:

---------------------------------------------------------------------------
TypeError
Traceback (most recent call last)
<ipython-input-76-35c8707b256e> in <module>()
----> 1 print count('items')

TypeError: 'dict' object is not callable

In [77]: print count('keys')
---------------------------------------------------------------------------
TypeError
Traceback (most recent call last)
<ipython-input-77-54ed4a05a3c7> in <module>()
----> 1 print count('keys')

TypeError: 'dict' object is not callable

In [78]:


Regards,
Hal