python dict

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         : Joyiscold
3#date           : 2020-02-01
4#====================================================
5
6thisdict = {
7	"brand": "Ford",
8 	"model": "Mustang",
9 	"year": 1964
10}
11
12#Assigning a value
13thisdict["year"] = 2018

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

1student_data = {
2  "name":"inderpaal",
3  "age":21,
4  "course":['Bsc', 'Computer Science']
5}
6
7#the keys are the left hand side and the values are the right hand side
8#to print data you do print(name_of_dictionary['key_name'])
9
10print(student_data['name']) # will print 'inderpaal'
11print(student_data['age']) # will print 21
12print(student_data['course'])[0]
13#this will print 'Bsc' since that field is an array and array[0] is 'Bsc'

1# decleration
2my_dict = {
3  'spam': 'eggs',
4  'foo': 4,
5  100: 'bar',
6  2: 0.5
7}
8
9# access single values from the dictionary
10print(my_dict['spam']) # eggs
11print(my_dict['foo']) # 4
12print(my_dict[100]) # bar
13print(my_dict[2]) # 0.5
14
15# iterate over the dictionary
16for key, value in my_dict.items():
17  print(key, value)
18
19# get length of the dictionary
20print(len(my_dict)) # 4
21
22# modify the dictionary
23my_dict['baz'] = 'qux' # adds a pair
24my_dict['baz'] = 'quxx' # also updates it
25del my_dict['spam'] # removes a pair
26
27# other methods
28print(my_dict.copy()) # Returns a copy of the dictionary
29print(my_dict.fromkeys('added', 100)) # Returns a dictionary with the specified keys and their values
30print(my_dict.get('foo')) # Returns the value of the specified key
31print(my_dict.items()) # Returns a list containing a tuple for each key value pair
32print(my_dict.keys()) # Returns a list containing the dictionaries keys
33print(my_dict.values()) # Returns a list of all the values in the dictionary
34my_dict.setdefault('a', 'b') # Returns the value of the specified key. If the key does not exist: insert the key, with the specified value
35my_dict.pop('foo') # Removes the element with the specified key
36my_dict.popitem() # Removes the last inserted key-value pair
37my_dict.update({'baz': 'val'}) # Updates the dictionary with the specified key-value pairs
38my_dict.clear() # Removes all the elements from the dictionary

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