The document discusses dictionaries in Python. It explains that a dictionary consists of keys and values, with keys usually represented as strings. It provides examples of creating dictionaries and accessing values using keys. It also discusses using loops to iterate through dictionaries and lists of dictionaries. Exercises are provided to create dictionaries with random values, retrieve values using keys, add/delete key-value pairs, and print keys and values.

1. Python with AI – I
Dictionaries

2. Dictionaries in python
• A dictionary consists of two things (a) keys (b) values

3. Dictionaries in python
• A dictionary consists of two things (a) keys (b) values
• Use strings to represent keys

4. Dictionaries in python
• A dictionary consists of two things (a) keys (b) values
• Use strings to represent keys
• Values can be anything

5. Dictionaries in python
• A dictionary consists of two things (a) keys (b) values
• Use strings to represent keys
• Values can be anything
• There are many ways to create a dictionary, we will look at one way to
do it:

6. Dictionaries in python
• A dictionary consists of two things (a) keys (b) values
• Use strings to represent keys
• Values can be anything

7. Print the entire dictionary
• Print(my_dict)
• Please inspect the format in which it is printed.
• Where do the : symbols show up?

8. Print the entire dictionary
• Print(my_dict)
• Please inspect the format in which it is printed.
• Where do the colon (:) symbols show up?
• Where do the commas (,) show up?

9. Exercise
• Create a dictionary, where the keys are one, two and the
corresponding values are 1 and 2

10. Exercise
• Create a dictionary, where the keys are one, two and the
corresponding values are 1 and 2
• Create a dictionary, where the keys are aiclub, PA1, M1 and the
corresponding values are website, python class, AI class.

11. Dictionaries in python
• Print a value in a dictionary

12. Exercise
• Print values of the first dictionary you created
• Print value corresponding to the key one
• Print value corresponding to the key two

13. Exercise
• Print values of the first dictionary you created
• Print value corresponding to the key one
• Print value corresponding to the key two
• Print values of the second dictionary you created
• Print value corresponding to the key aiclub
• Print value corresponding to the key M1
• Print value corresponding to the key PA1

14. Dictionaries in python
• Print a value in a dictionary
• Delete a value in a dictionary

15. Exercise
• Delete and print values of new dictionaries
• For the first dictionary
• Delete the value corresponding to the key one
• Print the value of dictionary
• For the second dictionary
• Delete the value corresponding to the key aiclub
• Print the value of dictionary

16. Dictionaries in python
• Print a value in a dictionary
• Delete a value in a dictionary
• Print all keys of a dictionary

17. Exercise
• Instead of printing the entire dictionary, please print only the keys of
the two dictionaries you created

18. Dictionaries in python
• Print a value in a dictionary
• Delete a value in a dictionary
• Print all keys of a dictionary
• Add values to a dictionary

19. Exercise
• Add the keys that you deleted from the 2 dictionaries back
• Print the two dictionaries

20. loops and dictionaries – use together
• Loops - recap
• The for loop is of the following form.
• The range indicates the number of times a statement will be implemented.
• There is a colon value to indicate the start of for loop.
• The code below is executed many times. The number of times it gets executed
depends on the values specified in range.
• Note that the code below the for statement is indented.

21. Loops - recap
• The for loop is of the following form.
• Try different values inside the brackets of range
• Note that everything with indentation below for loop is executed as a
part of the loop.

22. Loops and Dictionaries
• Exercise
a) Create a random number in the limits 0 and 10 using a random number
generator

23. Loops and Dictionaries
• Exercise
a) Create a random number in the limits 0 and 10 using a random number
generator
b) Create a list of length 10 using the random number generator (pick any
limits) – please use a loop

24. Loops and Dictionaries
• Exercise
a) Create a random number in the limits 0 and 10 using a random number
generator
b) Create a list of length 10 using the random number generator (pick any
limits) – please use a loop
c) Now create a dictionary using the values of the list as keys and the
corresponding values for each key can be another random number (pick any
limits).

25. Lists - recap
• A list holds ordered collection of items.
• And item can be a string or a number

26. Lists - recap
• A list holds ordered collection of items.
• And item can be a string or a number
• An item can be a dictionary too

27. List of dictionaries - Exercise
• Create a dictionary dict_1 with keys one, two, three and values 1, 2
and 3

28. List of dictionaries - Exercise
• Create a dictionary dict_1 with keys one, two, three and values 1, 2
and 3
• Create a dictionary dict_2 with keys one, two and three and values I,
II, III

29. List of dictionaries - Exercise
• Create a dictionary dict_1 with keys one, two, three and values 1, 2
and 3
• Create a dictionary dict_2 with keys one, two and three and values I,
II, III
• Create a list with these two dictionaries: list_dict = [dict_1, dict_2]

30. List of dictionaries - Exercise
• Create a dictionary dict_1 with keys one, two, three and values 1, 2
and 3
• Create a dictionary dict_2 with keys one, two and three and values I,
II, III
• Create a list with these two dictionaries: list_dict = [dict_1, dict_2]
• Print the value corresponding to the key one of first dictionary dict_1
from the list list_dict

31. List of dictionaries - Exercise
• Create a dictionary dict_1 with keys one, two, three and values 1, 2
and 3
• Create a dictionary dict_2 with keys one, two and three and values I,
II, III
• Create a list with these two dictionaries: list_dict = [dict_1, dict_2]
• Print the value corresponding to the key one of first dictionary dict_1
from the list list_dict
• Print the value corresponding to the key one of second dictionary
dict_2 from the list list_dict

32. Lets try it!
http://aiclub.world