dict.txt

                           Dictionary in python

Unlike sequences, which are indexed by a range of numbers, dictionaries are indexed by keys, which can be any immutable type; strings and numbers can always be keys.
*dictionary as a set of key: value pairs, with the requirement that the keys are unique (within one dictionary) in which key are given by us and we use this key to access an element .
A pair of braces creates an empty dictionary: {}.
Placing a comma-separated list of key:value pairs within the braces adds initial key:value pairs to the dictionary; this is also the way dictionaries are written on output. 
key should be unique and immutable type
dictionary are mutable we can change the value by using key.


we can have dictionary or list as a value for dictionary itself

dictunary.get(key)=return the value of key if key is not found then default value not an error

zip function is used to join two list and return zip object and we need to typecast  the type of object in form of dict or list or set
>>> a=[1,2,3,4,5,6]
>>> b=[7,8,9,10,11,12]
>>> z=zip(a,b)
>>> z=list(z)
>>> z
[(1, 7), (2, 8), (3, 9), (4, 10), (5, 11), (6, 12)]

>>> s={1:10,2:20}
>>> s
{1: 10, 2: 20}
>>> type(s)
<class 'dict'>
>>> s={}
>>> type(s)
<class 'dict'>
>>> s['manu']='gadha'
>>> s['shally']='intelligent'
>>> s
{'manu': 'gadha', 'shally': 'intelligent'}
>> s['shally']
'intelligent'
>>> s['shally']='syster'
>>> s
{'manu': 'gadha', 'shally': 'syster'}
>>> s['t']
Traceback (most recent call last):
  File "<pyshell#13>", line 1, in <module>
    s['t']
KeyError: 't'
>>> s.get('t')
>>> a=[1,2,3,4,5,6]
>>> s['lists']=a
>>> 
>>> s
{'manu': 'gadha', 'shally': 'syster', 'lists': [1, 2, 3, 4, 5, 6]}
>>> s['lists'][0]
1
>>> dictionary={1:23,3:42}
>>> s['dict']=dictionary
>>> s
{'manu': 'gadha', 'shally': 'syster', 'lists': [1, 2, 3, 4, 5, 6], 'dict': {1: 23, 3: 42}}