simple key value loop help

[siten0308]

Hello,

I have the following python code:

d = {'123':'John','123':'Steve','4929':'959','3491':'5','319':'Bob','name': 'john','code':6734, 'dept': 'sales'}

for k, v in d.items():
   if(k == '123'):
    print (v)

and the results should print out 2: which are Steve and John, however i only see steve printed out... not sure why? any help would be great.

thanks in advance :)

[nilamo]

A dictionary is a collection of key->value pairs. Duplicate keys don't make sense, so the last one evaluated is the one that will persist in the dict. ie: "John" isn't there, because you overwrote it with "Steve".

[ankit]

Hi dear,
If you want to print both the name with same value(or key value) then, you have to change your data type from dictionary to something like tuple , because you can keep the identically values there
hope it may help you.
for example :-

d = [(1,'abc'),(1,'xyz')]
for i in d:
    if i[0] == 1:
       print (i[1])

[perfringo]

You don't need to iterate over dictionary. You should go directly to key and associated value:

>>> d = {'123': 'John', '319': 'Bob'} 
>>> print(d['319'))
Bob

I also suggest to think whether current structure of data is suitable for task at hand. For example you can have list (or tuple) as value:

>>> d = {'123': ['John', 'Steve'], '319': ['Bob']}
>>> print(*d['123'])
John Steve
>>> ', '.join(d['123'])
John, Steve
>>> ', '.join(d['319'])
Bob

You can also have list of named tuples or dictionaries. Then you can iterate over list and look for match:

>>> d = [{'name': 'John', 'code': 123},
...      {'name': 'Steve', 'code': 123},
...      {'name': 'Bob', 'code': 319}]
>>> [record['name'] for record in d if record['code'] == 123]
['John', 'Steve']

[siten0308]

thank you all, this definitely helps me understand dictionary more, appreciate everyone's time and input.