dictionaries python code example

Example 1: dictionary in python does not support append operation

dict_append = {"1" : "Python", "2" : "Java"}
dict_append.update({"3":"C++"})  # append doesn't supported in dict 
								 # instead , use update in dict
print(dict_append)
# output : {'1': 'Python', '2': 'Java', '3': 'C++'}

Example 2: python dictionary

#Creating dictionaries
dict1 = {'color': 'blue', 'shape': 'square', 'volume':40}
dict2 = {'color': 'red', 'edges': 4, 'perimeter':15}

#Creating new pairs and updating old ones
dict1['area'] = 25 #{'color': 'blue', 'shape': 'square', 'volume': 40, 'area': 25}
dict2['perimeter'] = 20 #{'color': 'red', 'edges': 4, 'perimeter': 20}

#Accessing values through keys
print(dict1['shape'])

#You can also use get, which doesn't cause an exception when the key is not found
dict1.get('false_key') #returns None
dict1.get('false_key', "key not found") #returns the custom message that you wrote 

#Deleting pairs
dict1.pop('volume')

#Merging two dictionaries
dict1.update(dict2) #if a key exists in both, it takes the value of the second dict
dict1 #{'color': 'red', 'shape': 'square', 'area': 25, 'edges': 4, 'perimeter': 20}

#Getting only the values, keys or both (can be used in loops)
dict1.values() #dict_values(['red', 'square', 25, 4, 20])
dict1.keys() #dict_keys(['color', 'shape', 'area', 'edges', 'perimeter'])
dict1.items() 
#dict_items([('color', 'red'), ('shape', 'square'), ('area', 25), ('edges', 4), ('perimeter', 20)])

Example 3: Python New Disctionary

new_dict = dict()

#OR

new_dict = {}

Example 4: dictionary in python

# Dictionaries in Python are used to store set of data like Key: Value pair

# the syntax of a dictionary in Python is very simple we use {} inside that
	# we define {Key: Value}, to separate multiple values we use','
programming_dictionary = {
    "Bug": "An error in a program that prevents the program from running as expected.",
  
    "Function": "A piece of code that you can easily call over and over again.",
  
  	"Loop": "The action of doing sommething again and again",
}
# to retrieve the values from a dictionary we use the Key name as an Index
# retrieving the Function's definition
print(programming_dictionary["Function"])	# this will print the definition of Function

# if you wanna print all the entries in the dictionary you can do that by for loop
for key in programming_dictionary:
  print(programming_dictionary[key])	# prints all entries
  
# adding items to a dictionary
# the following code will add another entry to the dictionary called Variable
programming_dictionary["Variable"] = "The label to store some sort of data"
print(programming_dictionary["Variable"])

# editing the values of a key 
# editing the value of variable
programming_dictionary["Variable"] = "Variables are nothing but reserved memory locations to store values. This means that when you create a variableyou reserve some space in memory"

# if you learnt something from this please upvote it

Example 5: dictionary in python

tel = {'jack': 4098, 'sape': 4139}
tel['guido'] = 4127
print(tel)
# OUTPUT {'jack': 4098, 'sape': 4139, 'guido': 4127}
print(tel['jack'])
# OUTPUT 4098
del tel['sape']
tel['irv'] = 4127
print(tel)
# OUTPUT {'jack': 4098, 'guido': 4127, 'irv': 4127}
print(list(tel))
# OUTPUT ['jack', 'guido', 'irv']
print(sorted(tel))
# OUTPUT ['guido', 'irv', 'jack']
print('guido' in tel)
# OUTPUT True
print('jack' not in tel)
# OUTPUT False

Example 6: python make a dictionary

#title			: Dictionary Example
#author         : Joyiscold
#date           : 2020-02-01
#====================================================

thisdict = {
	"brand": "Ford",
 	"model": "Mustang",
 	"year": 1964
}

#Assigning a value
thisdict["year"] = 2018