4.8: List (container)

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Figure \(\PageIndex{1}\):The variable molar_Mass is a list. This image was taken from an IDE that displayed strings in red and floating numbers in green (Belford CC0.0)

Overview

• Use Brackets
  • Can have multiple types of objects
  • commas separate objects
• Lists are ordered
  • Support Indexing and Slicing
• Lists can be nested
• Lists are mutable (can be modified)
• Lists are an object class with methods

 

Methods

• append
• count
• extend
• insert
• pop
• remove
• reverse
• sort

molar_Mass=['hydrogen',1.00784,'helium',4.002602,'lithium', 6.941, 'beryllium', 9.012182]
print('List Created')

Hello world!

 

len(molar_Mass)

        hello world
      

 

molar_Mass=['hydrogen',1.00784,'helium',4.002602,'lithium', 6.941, 'beryllium', 9.012182]
print(f"There are {len(molar_Mass)} items in the list molar_Mass")

Hello world!

print every other item starting with first item (index number = 0)

molar_Mass[0::2]

        hello world
      

print every other item starting with first item (index number = 0) with a range of up to 4 (it does not print item with index =4)

molar_Mass[0:4:2]

        hello world
      

Print print every other item starting with second item (index number = 1)

molar_Mass[1::2]

        hello world
      

Create three lists

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]
print('List Created')

Hello world!

Print two of the lists, note they are printed as two separate lists

print(name_halogen,z_halogen)

        hello world
      

Combine the two lists into one and print it

print(name_halogen+a_halogen)

        hello world
      

create a new list and print it

halogen_masses=name_halogen+a_halogen
print(halogen_masses)

        hello world
      

 

print(name_halogen)

Hello world!

 

popped_halogen=name_halogen.pop()
print(name_halogen)
print(popped_halogen)

Hello world!

 

name_halogen.append(popped_halogen)
print(name_halogen)

        hello world
      

 

remove_bromine=name_halogen.pop(2)
print(name_halogen)
print(remove_bromine)
name_halogen.insert(2,remove_bromine)
print(name_halogen)

        hello world
      

 

halogen=[name_halogen, z_halogen,a_halogen]
print(f'{halogen}\n')

print(f'{halogen[0]}\n')
print(f'{halogen[0:][1]}\n')
print(f'{halogen[0:][0]}\n')
print(f'{halogen[0][0:]}\n')
print(f'{halogen[2][0]}\n')

        hello world
      

 

 

random_list=[22,41,16,444,224]
print(random_list)
random_list.reverse()
print(random_list)
random_list.sort()
print(random_list)

Hello world!