This document discusses various dictionary functions and methods in Python. It explains how to get the length of a dictionary using len(), access items and values using .items() and .values(), create dictionaries from keys using .fromkeys(), shallow copy a dictionary using .copy(), get a sorted list of keys using sorted(), and calculate the maximum, minimum and sum of dictionary keys using max(), min() and sum(). Functions like .get(), .keys(), .update() are also covered.

1. DICTIONARY FUNCTIONS AND METHODS
-RANJANA.V

2. GETTING LENGTH OF A DICTIONARY
THE LEN( ) FUNCTION
Syntax - len(<dictionary>)
 For example –
 tit={'name':'tom', 'sal':'123',
'age':'14'}
>>>len(tit)
3

3. ACCESSING ITEMS, KEYS AND VALUES
 Syntax- <dictionary>.get( key )
 To get the value of a key
For example:
tit={'name':'tom', 'sal':'123', 'age':'14'}
>>>tit.get(‘age’)
‘14’
 It returns all the items in the dictionary as a
sequence of key,value pair
 It returns them as tuples
For example:
tit={'name':'tom', 'sal':'123', 'age':'14'}
>>>tit.items()
([ ('name':'tom‘), ('sal':'123‘),( 'age':'14‘)
])
The item( ) method
The get( ) method

4.  It returns all the keys in a dictionary
 It returns them in list form
 Syntax- <dictionary>.keys( )
 For example:
 tit={'name':'tom', 'sal':'123',
'age':'14'}
>>>tit.keys( )
['name‘, 'sal’, 'age']
 It returns all the values of a
dictionary
 It returns in list form
 Syntax - <dictionary>. values()
 For example:
 tit={'name':'tom', 'sal':'123', 'age':'14'}
>>>tit.values( )
[‘tom’, ‘123’, ‘14’]
The keys() method The values( ) method

5. CREATING DICTIONARIES FROM KEYS
 It contains sequence of keys of the new
dictionary
 The key can be in form of list or tuple
 It has one common value
 If no value given , value None ,is
assigned to value
 SYNTAX-
 dict.fromkeys(<keys sequence>,
The fromkeys( ) method
 nd=dict.fromkeys([2,3,4,5,], 100)
>>>nd
{2:100, 3:100 , 4:100, 5:100}
nd=dict.fromkeys((2,3,4,5,))………..ex-2
>>>nd
{2:None,3:None,4:None,5:None}

6. THE UPDATE( ) METHODS
 This method merges key: value pairs from the new dictionary into the original dictionary
 Existing keys will be updated with new values
 Syntax-
 <dictionary>.update(<new dictionary>)
 For example:
 get={‘a’:5,’b’:2,’c’:3, r:1}
 Tit={‘a’:11’,sam’:12,’c’:’14’}
>>>get.update(tit)
>>>get
{‘a’:11,’sam’:12,’b’:2, ‘c’:14,’r’:1}

7. SHALLOW COPY
 Syntax-<dict>.copy
 For example:
 tit={'name':'tom', 'sal':'123', 'age':'14'}
 tit2=tit.copy( )
 print(tit2)
 tit={'name':'tom', 'sal':'123', 'age':'14'}
 tit2[ham]=‘food’ ….
 tit2={'name':'tom', 'sal':'123', 'age':'14‘,’ham’:’food’}
 tit={'name':'tom', 'sal':'123', 'age':'14'}
Updating

8. GET SORTED LIST OF KEYS – THE SORTED( ) FUNCTION
Here keys are sorted sorted(<dict>) for ascending order
It returns in form of list sorted(<dict>,[reverse=True])
 tit={5:’jas’,22:’sam’,13:’tom’,4:’tim’}
 tit2=sorted(tit)
 print(tit2)
 [4,5,14,22]
ascending order
 tit={5:’jas’,22:’sam’,13:’tom’,4:’tim’}
 tit2=sorted(tit2,[reverse=true])
 print(tit2)
 [22,13,5,4]
 Descending order

9. CALCULATING MAXIMUM , MINIMUM , SUM- MAX() , MIN(), SUM(),
FUNCTIONS
 Tit={5:’jas’,22:’sam’,13:’tom’,4:’tim’} Tit={5:’jas’,22:’sam’,13:’tom’,4:’tim’}
 Print (max(tit)) Print (min(tit))
 22 4
 These function works on keys
max min

10. SUM()
 sums() can only work with dictionary having keys which are addition compatible
 Example
 d2={‘green’:20,’blue’:30,yellow:40,’grey’:50}
 Print(sum(d2))
 d3={5:’jas’,22:’sam’,13:’tom’,4:’tim’}
 Print(sum(d3))
 44
error

11. THANK YOU
RANJANA12MALATH@GMAIL.COM