python dictionary methods

1#Creating dictionaries
2dict1 = {'color': 'blue', 'shape': 'square', 'volume':40}
3dict2 = {'color': 'red', 'edges': 4, 'perimeter':15}
4
5#Creating new pairs and updating old ones
6dict1['area'] = 25 #{'color': 'blue', 'shape': 'square', 'volume': 40, 'area': 25}
7dict2['perimeter'] = 20 #{'color': 'red', 'edges': 4, 'perimeter': 20}
8
9#Accessing values through keys
10print(dict1['shape'])
11
12#You can also use get, which doesn't cause an exception when the key is not found
13dict1.get('false_key') #returns None
14dict1.get('false_key', "key not found") #returns the custom message that you wrote 
15
16#Deleting pairs
17dict1.pop('volume')
18
19#Merging two dictionaries
20dict1.update(dict2) #if a key exists in both, it takes the value of the second dict
21dict1 #{'color': 'red', 'shape': 'square', 'area': 25, 'edges': 4, 'perimeter': 20}
22
23#Getting only the values, keys or both (can be used in loops)
24dict1.values() #dict_values(['red', 'square', 25, 4, 20])
25dict1.keys() #dict_keys(['color', 'shape', 'area', 'edges', 'perimeter'])
26dict1.items() 
27#dict_items([('color', 'red'), ('shape', 'square'), ('area', 25), ('edges', 4), ('perimeter', 20)])

1#title			:Dictionary Example
2#author         :Josh Cogburn
3#date           :20191127
4#github         :https://github.com/josh-cogburn
5#====================================================
6
7thisdict = {
8	"brand": "Ford",
9 	"model": "Mustang",
10 	"year": 1964
11}
12
13#Assigning a value
14thisdict["year"] = 2018

1# PYTHON DICTIONARY METHODS
2METHOD	      DESCRIPTION
3clear()	      Removes all the elements from the dictionary
4copy()	      Returns a copy of the dictionary
5fromkeys()	  Returns a dictionary with the specified keys and value
6get()	      Returns the value of the specified key
7items()	      Returns a list containing a tuple for each key value pair
8keys()	      Returns a list containing the dictionary's keys
9pop()	      Removes the element with the specified key
10popitem()	  Removes the last inserted key-value pair
11setdefault()  Returns the value of the specified key. If the key does not exist: 
12                insert the key, with the specified value
13update()	  Updates the dictionary with the specified key-value pairs
14values()	  Returns a list of all the values in the dictionary

1thisdict = {
2  "key1" : "value1"
3  "key2" : "value2"
4  "key3" : "value3"
5  "key4" : "value4"
6}

1thisdictionary = {'key':'value','key1':'value1'}
2print(thisdictionary['key'])

1dictionary methods