DICTIONARY OPERATIONS:
======================
1) FINDING LENGTH OF THE DICTIONARY:
===================================
len():
=====
using len() we can find the length of any collection.
Syntax:
	len(dictionary-name)

# WAP TO FIND THE LENGTH OF THE DICTIONARY

d = eval(input("Enter a dictionary:"))

print("The Length of the dictionary is = ",len(d))

count = 0
for cnt in d:
    count += 1

print("The Length of the dictionary is = ",count)

================================================
Getting values from the Dictionary:
===================================
dict-name[key] ==> values

get()
=====
we can use get() to access the values of the dictionary.
Syntax:
	dict-name.get(key)

Note:
=====
1) If the specified key is in the dictionary ==> associated value can be returned by the get()
2) If the specified key is not in the dictionary ==> None.
3) Instead to return 'None' when the specified key is not in the dictionary
to return some default value:
Syntax:
	dict-name.get(key,default-value)

d = {'apple' : 10, 'banana' : 15, 'mango' : 25, 'kiwi' : 35, 'papaya' : 20}

print(d['mango'])

res = d.get('mango')

print(res)
print(d.get('jackfruit'))
print(d.get('jackfruit',0))

=============================================
Getting of Keys from the dictionary:
====================================
keys():
======
return all the associated keys of dictionary.
Syntax:
	dict-name.keys()

Getting of values from the dictionary:
======================================
values():
return all associated values of the dictionary.
Syntax:
	dict-name.values()

d = eval(input("Enter a Dictionary:"))

keys = d.keys()
values = d.values()

print("All The Keys of the Dictionary = ",keys)
print("All The Values of the Dictionary = ",values)

====================================

# WAP TO PRINT ALL THE KEYS OF THE DICTIONARY

d = eval(input("Enter a dictionary:"))

for keys in d:
    print(keys)

for k in d.keys():
    print(k)

================================

# WAP TO PRINT ALL THE VALUES OF THE DICTIONARY

d = dict({'apple' : 100, 'banana' : 125, 'mango' : 200, 'kiwi' : 175})

for values in d:
    print(d[values])
print()

for v in d.values():
    print(v)

===========================================
Getting both keys and values in arbitrary from the dictionary:
==============================================================
items():
========
Syntax:
	dict-name.items()
return: list of tuples with keys and values
ex: [(key1,val1),(key2,val2),(key3,val3)]

d = eval(input("Enter a dictionary:"))

items = d.items()

print(items)

for item in d.items():
    print(item)
========================================

copy()
======
to create a dictionary from other dictionary, copy() can use.

Syntax:
	new-dict = old-dict.copy()

# cloning of the dictionary

d = {'name' : 'Kumar', 'age' : 26, 'Course' : 'Python','Duration' : 4}

print(id(d))
print(d)

cd = d.copy()

print(id(cd))
print(cd)

cd['name'] = 'sahithi'

print(d)
print(cd)

d['name'] = 'Ashwini'

print(d)
print(cd)

===================================

Aliasing of Dictionary Data:
===========================
using assignment operator

d = {'a' : 100, 'b' : 200, 'c' : 300}

cd = d

print(d);print(cd)
print(id(d));print(id(cd))

cd['d'] = 400
d['a'] = 111

print(d);print(cd)

========================================

# WAP TO FIND THE NUMBER OF OCCURRENCES OF EACH LETTER PRESENT IN THE GIVEN STRING
# 'python'
# output: {'p' : 1, 'y' :1, 't' : 1, 'h' : 1, 'o' : 1,'n' :1}
# 'apple'
# output: {'a' : 1, 'p' : 2, 'l' : 1,'e' :1}

data = input("Enter a string data:")    # apple

d = dict()

for cnt in data:
    d[cnt] = d.get(cnt,0) + 1

for k,v in d.items():
    print(k,"occurred",v,"times")

======================================================

Comprehensions
===============

very easy and compact way to create collection objects like: list, set, dictionary from any iterable object like: range(), list, tuple etc. based on some condition.

Syntax:
	identifier = [condition for lv in collection/range] ==> List Comprehension
	identifier = {condition for lv in collection/range} ==> set comprehension
	identifier = {key : value for condition for lv in collection/range} ==> Dictionary Comprehension

Note: Tuple Comprehension is not possible in Python.
	

# dictionary Comprehensions

s = {k : k * k for k in range(1,11)}
d = {i : i + 2 for i in range(10,16)}
d1 = {j : j % 2 == 0 for j in [1,2,3,4,5,6,7,8,9,10]}

print(s);print(type(s))
print(d)
print(d1)

# set comprehensions

s1 = {x * x for x in range(6)}

print(s1)

# Tuple Comprehensions ==> not possible in python

t1 = (d * 3 for d in range(10))

print(type(t1))

for i in t1:
    print(i,end = "\t")
print()

# List Comprehension
ld = [s * 2 for s in range(10)]
print(ld)