Buy Me a Coffee☕ *My post explains useful functions. You can create a dictionary as shown below. *dict() can also create a dictionary: v = {'name':'John', 'age':36} v = dict(name='John', age=36) v = dict([('name', 'John'), ('age', 3…

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*My post explains useful functions.

You can create a dictionary as shown below. *dict() can also create a dictionary:

v = {'name':'John', 'age':36}

v = dict(name='John', age=36)

v = dict([('name', 'John'), ('age', 36)])



v = {'person1':{'name':'John', 'age':36},

     'person2':{'name':'Tom', 'age':24}}

v = dict(person1=dict(name='John', age=36),

         person2=dict(name='Tom', age=24))

v = dict([('person1', dict([('name', 'John'), ('age', 36)])),

          ('person2', dict([('name', 'Tom'), ('age', 24)]))])

You can access and modify a dictionary with a key in each [] as shown below. *A dictionary is mutable so you can modify a dictionary:

*Memos:

items() can get zero or more keys and values from a dictionary. *There are no arguments.

keys() can get zero or more keys from a dictionary. *There are no arguments.

values() can get zero or more values from a dictionary. *There are no arguments.

v = {'name':'John', 'age':36}

v = dict(name='John', age=36)

v = dict([('name', 'John'), ('age', 36)])



print(v['name'], v['age'])

# John 36



v['name'] = 'David'

v['gender'] = 'Male'



print(v)

# {'name': 'David', 'age': 36, 'gender': 'Male'}



print(v.items())

# dict_items([('name', 'David'), ('age', 36), ('gender', 'Male')])



print(v.keys())

# dict_keys(['name', 'age', 'gender'])



print(v.values())

# dict_values(['David', 36, 'Male'])

v = {'person1':{'name':'John', 'age':36},

     'person2':{'name':'Anna', 'age':24}}

v = dict(person1=dict(name='John', age=36),

         person2=dict(name='Tom', age=24))

v = dict([('person1', dict([('name', 'John'), ('age', 36)])),

          ('person2', dict([('name', 'Tom'), ('age', 24)]))])



print(v['person1'], v['person2'])

# {'name': 'John', 'age': 36} {'name': 'Tom', 'age': 24}



print(v['person1']['name'], v['person1']['age'],

      v['person2']['name'], v['person2']['age'])

# John 36 Anna 24



v['person1']['name'] = 'David'

v['person2']['gender'] = 'Female'

v['person3'] = {'name':'Tom', 'age':18, 'gender':'Male'}



print(v)

# {'person1': {'name': 'David', 'age': 36},

#  'person2': {'name': 'Anna', 'age': 24, 'gender': 'Female'},

#  'person3': {'name': 'Tom', 'age': 18, 'gender': 'Male'}}

You can use get() to get a value from a dictionary by a key as shown below:

*Memos:

The 1st argument is key(Required) for a key.

The 2nd argument is default(Optional-Default:None) to return a value when a key doesn't exist.

Don't use key= and default=.

v = {'name':'John', 'age':36}



print(v.get('name')) # John

print(v.get('gender')) # None

print(v.get('gender', "Doesn't exist!")) # Doesn't exist!

v = {'person1':{'name':'John', 'age':36},

     'person2':{'name':'Anna', 'age':24}}

print(v.get('person2')) # {'name': 'Anna', 'age': 24}

print(v['person2'].get('name')) # Anna

You can use update() to get a value from a dictionary by a key as shown below:

*Memos:

The 1st argument is key(Required) for a key.

The 2nd argument is default(Optional-Default:None) to return a value when a key doesn't exist.

Don't use key= and default=.

v = {'name':'John', 'age':36}



v.update({'name':'David'})

print(v) # {'name': 'David', 'age': 36}

v = {'person1':{'name':'John', 'age':36},

     'person2':{'name':'Anna', 'age':24}}

v.update({'person1':{'name':'David'}})

v['person2'].update({'name':'Tom'})

print(v) # {'person1': {'name': 'David'},

         #  'person2': {'name': 'Tom', 'age': 24}}