6.2.1 Creating a Dictionary

  • Create a dictionary by enclosing in curly braces, {}, a comma-separated list of key–value pairs, each of the form key: value.
  • Create an empty dictionary with {}.
In [1]:
country_codes = {'Finland': 'fi', 'South Africa': 'za', 
                  'Nepal': 'np'}
In [2]:
country_codes
Out[2]:
{'Finland': 'fi', 'South Africa': 'za', 'Nepal': 'np'}
  • Dictionaries are unordered collections.
  • Do not write code that depends on the order of the key–value pairs.

Determining if a Dictionary Is Empty

In [3]:
len(country_codes)
Out[3]:
3
  • Can use a dictionary as a condition to determine if it’s empty—non-empty is True and empty is False
In [4]:
if country_codes:
    print('country_codes is not empty')
else:
    print('country_codes is empty')
    

country_codes is not empty
In [5]:
country_codes.clear()
In [6]:
if country_codes:
    print('country_codes is not empty')
else:
    print('country_codes is empty')
    

country_codes is empty

©1992–2020 by Pearson Education, Inc. All Rights Reserved. This content is based on Chapter 6 of the book Intro to Python for Computer Science and Data Science: Learning to Program with AI, Big Data and the Cloud.

DISCLAIMER: The authors and publisher of this book have used their best efforts in preparing the book. These efforts include the development, research, and testing of the theories and programs to determine their effectiveness. The authors and publisher make no warranty of any kind, expressed or implied, with regard to these programs or to the documentation contained in these books. The authors and publisher shall not be liable in any event for incidental or consequential damages in connection with, or arising out of, the furnishing, performance, or use of these programs.