Lists in Python
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This document provides an overview of lists in Python. It discusses what lists are, how to access elements in a list using indexes, slicing lists, changing and removing list elements, sorting lists, and other common list operations. It also covers related data types like tuples and strings. Lists allow storing multiple values in a sequence and provide various methods to manipulate element values and order.
![The List Data Type
• A list is a value that contains multiple values in an ordered sequence
• A list value looks like this: ['cat', 'bat', 'rat', 'elephant']
• Values inside the list are also called items](https://image.slidesharecdn.com/lists-200306063227/85/Lists-in-Python-3-320.jpg)
Lists in Python
- 1. Lists in Python Md. Shafiuzzaman Lecturer, Dept. of CSE, JUST
- 2. Why list?
- 3. The List Data Type • A list is a value that contains multiple values in an ordered sequence • A list value looks like this: ['cat', 'bat', 'rat', 'elephant'] • Values inside the list are also called items
- 4. Getting Individual Values in a List with Indexes
- 5. Getting Individual Values in a List with Indexes • Python will give you an IndexError error message if you use an index that exceeds the number of values in your list value • Indexes can be only integer values, not floats
- 8. Getting Sublists with Slices • A slice can get several values from a list, in the form of a new list
- 9. Getting Sublists with Slices
- 10. Getting a List’s Length
- 11. Changing Values in a List with Indexes
- 12. List Concatenation and List Replication
- 13. Removing Values from Lists
- 14. Using for Loops with Lists
- 15. Using for Loops with Lists
- 16. Using for Loops with Lists
- 17. Exercise
- 18. Solution
- 19. The in and not in Operators • You can determine whether a value is or isn’t in a list with the in and not in operators.
- 20. The in and not in Operators
- 23. Methods • A method is the same thing as a function, except it is “called on” a value • Example: spam.index('hello') • Each data type has its own set of methods • List data type has several methods for finding, adding, removing, and otherwise manipulating values in a list
- 24. Finding a Value in a List with the index() Method
- 25. Finding a Value in a List with the index() Method • When there are duplicates of the value in the list, the index of its first appearance is returned
- 26. Adding Values to Lists: append()
- 27. Adding Values to Lists: insert()
- 28. Removing Values from Lists with remove()
- 29. Removing Values from Lists with remove()
- 30. Removing Values from Lists with remove()
- 31. del statement vs remove() • del statement is good to use when you know the index of the value you want to remove from the list • remove() method is good when you know the value you want to remove from the list
- 32. Practice Projects: Comma Code
- 33. Sorting the Values in a List with the sort() Method
- 34. Sorting the Values in a List with the sort() Method
- 35. Sorting the Values in a List with the sort() Method • sort() method sorts the list in place; don’t try to capture the return value by writing code like spam = spam.sort() • you cannot sort lists that have both number values and string values in them
- 36. Sorting the Values in a List with the sort() Method sort() uses “ASCIIbetical order” rather than actual alphabetical order for sorting strings
- 37. Sort the values in regular alphabetical order
- 39. List-like Types: Strings • Store your name in name variable and type the following code
- 40. Lists vs String • List -> mutable: It can have values added, removed, or changed • String -> immutable: It cannot be changed
- 41. “mutate” a string: slicing and concatenation
- 42. The Tuple Data Type • Tuples are immutable • Tuples cannot have their values modified, appended, or removed
- 44. Converting Types with the list() and tuple() Functions
- 45. References
- 46. References
- 48. Copy Module’s copy() and deepcopy() Functions