Dictionaries

Dictionaries in Python

# Define dict:
dict = {
	'k1': 'some data',
	7: ['can', 'be', 'a', 'list']
}

# Dictionaries are not position oriented, they are key oriented
# To get the data:
dict['k1'] # prints 'some data'

print(dict[7]) # prints ['can', 'be', 'a', 'list']

Dictionaries are mutable and can be changed

dict[7] = 'new value'

You cannot sort dictionaries, you should use keys to get the data

people_weight_dict = {
	'john': 123,
	'mike': 170,
	'robert': 167
}

# To change john's weight you would do
people_weight_dict['john'] = 134

You can pop items from dictionaries

people_weight_dict.pop('mike')

Syntax:

dict.pop('key')

Clear method

people_weight_dict.clear()
# It will still be a dictionary but it will be an empty one

Adding items to dictionary:

people_weight_dict = {
	'john': 123,
	'mike': 170,
	'robert': 167
}
# Adding the data
people_weight_dict['new_key'] = 'new data to be added'

# At this point the dict has been permanently modified and adjusted with a new entry

Accessing item from a list in the dict

people_weight_dict = {
	'john': 123,
	'mike': 170,
	'robert': 167,
	'items': ['apple', 'banana', 'orange']
}

print(people_weight_dict['items'][2]) # prints orange

Accessing items from a dictionary in a list in a dict

people_weight_dict = {
	'john': 123,
	'mike': 170,
	'robert': 167,
	'items': ['apple', 'banana', {'k1': 'some value'}]
}
print(people_weight_dict['items'][2]['k1']) # prints 'some value'

Remove items for dictionary:

people_weight_dict = {
	'john': 123,
	'mike': 170,
	'robert': 167,
	'items': ['apple', 'banana', {'k1': 'some value'}]
}

people_weight_dict.pop['items']
print(people_weight_dict) 
# It will print:
people_weight_dict = {
	'john': 123,
	'mike': 170,
	'robert': 167
}