Learning Python -Dictionaries

Continuing with my notes on learning Python. A brief overview of Dictionaries in Python from the Python Dev Bootcamp.

• Are unordered mappings
• Key-value pair
• Do not need to know the exact index position
• Just need to know the key in order to know the value
• Uses curly braces and colons to signify the keys and their associated values
• {‘key1′:’value1′,’key2′:’value2’}
• Dictionaries are unordered and cannot be sorted.
  • Cannot sort a dictionary
• Lists on the other hand can be retrieved by location
• Dictionaries can hold multiple data types include holding lists, or a dictionary within a dictionary
• Calling a list within a key
  • d = {‘k1′:123,’k2′:[0,1,5],’k3’:{‘insideKey’:100}}
  • d[‘k2’][2]
  • You get 5
• Appending to a dictionary
  • d[‘key4’] = 300
• Overwrite
  • d[‘k2’]=26
• Additional Functions
  • .keys() – shows you a list of keys in the dictionary
  • .values() – shows you the list of values in the dictionary
  • .items() – shows you the list of pairings
  • dict_items([(‘k1’, ‘New Number’), (‘k2’, [0, 1, 5]), (‘k3’, {‘insideKey1’: 100, ‘insidekey2’: 125}), (‘k4’, 75.5)])
    • ^ Shown as a Tuple

How I got into Learning to Code in Python.