4.9: Dictionary (container)

Figure \(\PageIndex{1}\): Copy and Paste Caption here. (Copyright; author via source)

Overview

Use KEY:VALUE Pair

• Use Curly Brackets
• Mutable
• Unordered
  • use KEY:VALUE pair separated by commas
• Values can be
  • lists
  • other dictionaries
  • strings, numbers
• Are an object class with methods

Simple Dictionary

z_alkali_dict={"Lithium":3,"Sodium":11,"Potassium":19, "Rubidium":37, "Caesium":55,"Francium":87}
#call the dictionary
z_alkali_dict

Hello world!

Dictionary of lists

First, create the lists.  Note, nothing happens as you have to print something, add  the following to the end of the script

print("list created")

name_halogen=['fluorine', 'chlorine', 'bromine', 'iodine', 'astatine','tennessine']
z_halogen=[9,17,35,53,85,117]
a_halogen=[18.99840316,35.45,79.90,126.9045,209.98715,294.211]
symbol_halogen=["F","Cl","Br","I","At","Ts"]

Hello world!

Make the dictionary and call it

hal_dict={'name':name_halogen,"atomic_number":z_halogen,"atomic_weight":a_halogen}
#call it
hal_dict

        hello world
      

Use Key to Call Values

Here we can use a key to get its value

print("the names of the halogens are ", hal_dict['name'])

        hello world
      

After running the above code, modify it to get the atomic weights of the halogens

Use list index numbers

print("The heaviest halogen is ", hal_dict['name'][-1])
print("The heaviest halogen is", hal_dict['name'][-1],", it weighs", hal_dict['atomic_weight'][-1],"amu.")

Hello world!

Methods

hal_dict['name'][2].upper()

        hello world
      

Print the keys

hal_dict.keys()

Hello world!

Print the values

hal_dict.values()

        hello world
      

Print the

print(hal_dict)
print("\n 5*' * '\n")
hal_dict.items()

Hello world!

 

 

 

 

 

 

 

 

 

 

 

Methods