Dictionary Operations
======================
Ex:
	Web application
		Facebook
		Registration
			Name
			Mail
			DOB
			Mobile
				Register

Facebook from local computer ==========> Database
		Name	Mail	DOB	Mobile	
		XYZ	xyz@m	22-3	xxxxxx

-> Dictionary is a collection which can use to store the data in the format of key-value pairs.
Syntax:
	dictionary-name = {key1 : value1, key2: value2, key3: value3,...}
Properties:
===========
1) Is a pre-defined/built-in datatype with the class name of "dict".
2) Dictionary is the collection of items, that each item is the key-value pair.
3) All keys of the dictionary must be "unique".
(No duplication is allowed for the keys)
	If any key of the dictionary is duplicated:
		then: the duplicated key must be upgraded with the latest definition.
4) Dictionary is ordered data structure.
5) Values of the dictionary may or may not be unique.
6) Keys in a dictionary are of any type.
7) Values in a dictionary are of any type.
8) No other collections like: list, tuple etc., allowed as keys in a dictionary.
9) Any collection we can consider as value in a dictionary.
10) Dictionary is not an index based.
11) Slicing is also not possible.
12) Dictionary elements can allow to access using keys.
13) Dictionary is mutable.

d = {'a':11,'b':12,'c':13,'d':14}
d1 = {'p':101,'q':111,'r':121,'p': 97}
d2 = {'x':11,'y':11,'z':11}
d3 = {True:'pqr',1-2j:2-3j,1.23:False,12:'p'}
# d4 = {[1,2,3]:12,(1,4,5,8):'pqrst'}
d4 = {'p':[1,3,5,7,9],'q':(1,2,3,4,5)}

print(type(d))
print(d)
print(d1)
print(d2)
print(d3)
print(d4)

# print(d[0])
print(d['c'])
print(d1['r'])
print(d2['z'])
print(d3[True])

print("Before the change in the dictionary:")
print(id(d))
print(d)

d['c'] = 1321

print("After the change in the dictionary:")
print(id(d))
print(d)

Adding of new elements into dictionary:
=======================================
Syntax:
	dictionary-name[key] = value;

# WRITE A PROGRAM TO ENTER NAME AND PERCENTAGE IN A DICTIONARY AND DISPLAY INFROMATION ON
# THE SCREEN.

# take an empty dictionary
record = {}

# take count for number of students
n = int(input("Enter number of students:")) # 5

# looping to enter student data to the record one after another.
i = 1   # initialization for while loop
while i <= n:
    name = input("Enter Student name:")
    marks = input("Enter % of Marks of Student:")
    record[name] = marks    # can help to make dictionary element
    i = i + 1

print("Name of the student","\t","Marks of the student")
for x in record:
    print("\t",x,"\t\t\t\t",record[x])

=======================================================
Dictionary Methods:
===================
eval():
======
-> can use to define the dictionary in the run time.
Syntax:
	dictionary-name = eval(input("Enter some dictionary:"))

for creating the empty dictionary:
1) {}:
=====
2) dict():
==========

# d1 = eval(input("Enter a dictionary:"))
#
# print(d1)

d2 = {}
d3 = dict()

print(d2)
print(d3)

print(type(d2))
print(type(d3))

3) len():
========
-> to find the length, len() can be used.
Syntax:
	len(dictionary-name)

4) get():
=========
-> can use to get the corresponding values based on the given keys.
Syntax:
	dictionary-name.get(key)

-> get() can used to defined some default value for any key.
If the specified key in get() is already existed:
	get() can return "original value"
where as the specified key is not exist:
	get() can return its default value
Syntax:
	dictionary-name.get(key, default-value)

d = {'apple':121,'banana':101,'cherry':321,'papaya':98,'mango':324}

print(d.get('apple'))
print(d.get('banana'))
print(d.get('cherry'))
print(d.get('papaya'))
print(d.get('mango'))

y = d.get('kiwi',123)
x = d.get('apple',212)

print(x)
print(y)