Part 2 - Python Tutorial | Introduction to Lists
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The document is a comprehensive guide to using lists in Python, covering topics such as list creation, element access, data types, and common operations like insertion and deletion. It explains the differences between mutable and immutable data types, provides methods for organizing and sorting lists, and discusses the use of negative indexing. Key functionalities and examples are provided to help learners understand how to effectively work with lists in their programming.
![LISTS IN PYTHON
• Use square brackets ([]) to represent a list
• Individuals elements are separated by a comma
• Printing a list](https://image.slidesharecdn.com/listsinpython-200908053107/85/Part-2-Python-Tutorial-Introduction-to-Lists-4-320.jpg)
![SORTING A LIST
• Putting the elements in a particular order
• Increasing order
• Decreasing order
• Numbers = [2, 1, 3]
• Increasing = [1, 2, 3]
• Decreasing = [3, 2, 1]](https://image.slidesharecdn.com/listsinpython-200908053107/85/Part-2-Python-Tutorial-Introduction-to-Lists-29-320.jpg)
![SORTING A LIST OF STRINGS
• Alphabetical order
• Names = [‘Shivam’, ’Anil’, ‘Navneet’]
• Increasing alphabetical order = [‘Anil’, ‘Navneet’, ‘Shivam’]
• Decreasing alphabetical order = [‘Shivam’, ‘Navneet’, ‘Anil’]](https://image.slidesharecdn.com/listsinpython-200908053107/85/Part-2-Python-Tutorial-Introduction-to-Lists-30-320.jpg)
Part 2 - Python Tutorial | Introduction to Lists
- 1. PART 2 LISTS IN PYTHON • WANT TO LEARN PYTHON PROGRAMMING? (SUBTITLES) • SUBSCRIBE • TELEGRAM – FreeCodeSchool • Twitter – shivammitra4 • LinkedIn – shivammitra • Link in description • INSTALLING PYTHON • VARIABLES AND DATA TYPES • PLAYLIST LINK IN DESCRIPTION
- 2. STORING MULTIPLE NAMES ? • 5 names, 10 names …. 100 names • Storing it in strings doesn’t scale well • Storing multiple numbers • Code clarity • Slow access
- 3. INTRODUCING LISTS • A list is a collection of items in a particular order • List of • Names • Places • list of digits • list of colors • Good to name your list names as plurals – names, places etc
- 4. LISTS IN PYTHON • Use square brackets ([]) to represent a list • Individuals elements are separated by a comma • Printing a list
- 5. ACCESSING ELEMENTS IN A LIST • Lists are ordered • Access an element by its position or index • In Python and most languages, list numbering starts from 0th position • This is very important
- 6. USE STRING METHODS ON THESE ELEMENTS
- 7. REMEMBER THIS IMPORTANT THING • Each index in a list contains a data type – integers, float, strings etc • Instead to using multiple variable names, you are using a single variable name to store all these • All functions/operations on a data type applies here to elements
- 8. CAN WE STORE DIFFERENT DATA TYPES IN A LIST ? But mostly we will store same type of data
- 9. LENGTH OF THE LIST USING LEN() FUNCTION
- 10. ACCESSING LAST ELEMENTS IN A LIST
- 11. NEGATIVE INDEXING IN PYTHON THIS WILL BE FASTER THAN THE LAST METHOD
- 12. STRINGS VS LISTS IN PYTHON
- 13. MODIFYING AN ELEMENT - LIST VS STRING
- 14. MUTABLE VS IMMUTABLE DATA TYPES • Immutable data type • The value/data cannot be changed • Example: strings, integers, floats etc • Mutable data type • The value/data can be changed • Example – lists • More about this in a separate video
- 15. INSERTING ELEMENTS TO A LIST
- 16. INSERTING ELEMENTS AT THE END OF A LIST
- 17. • This is very common • As data is mostly known after the program starts running
- 18. INSERTING ELEMENTS AT ANY POSITION
- 20. REMOVING ELEMENTS FROM A LIST
- 21. REMOVING USING DEL STATEMENTS
- 22. REMOVING USING POP METHOD • The pop() method removes the last item in a list, but it lets you work with that item after removing it
- 23. POPPING ITEMS FROM ANY POSITION IN THE LIST
- 24. WHEN TO USE DEL VS POP ?
- 25. REMOVING AN ELEMENT BY VALUE
- 26. REMOVING AN ELEMENT NOT IN A LIST
- 27. CAN DUPLICATES BE REMOVED ? • Removes first matching value • USING REMOVE AGAIN WILL DO
- 29. SORTING A LIST • Putting the elements in a particular order • Increasing order • Decreasing order • Numbers = [2, 1, 3] • Increasing = [1, 2, 3] • Decreasing = [3, 2, 1]
- 30. SORTING A LIST OF STRINGS • Alphabetical order • Names = [‘Shivam’, ’Anil’, ‘Navneet’] • Increasing alphabetical order = [‘Anil’, ‘Navneet’, ‘Shivam’] • Decreasing alphabetical order = [‘Shivam’, ‘Navneet’, ‘Anil’]
- 31. SORTING A LIST PERMANENTLY WITH SORT FUNCTION BY DEFAULT, SORT() SHORTES IN INCREASING ORDER
- 32. SORTING IN REVERSE ALPHABETIC ORDER
- 34. SORTING A LIST TEMPORARILY WITH SORTED FUNCTION • To maintain the original order of a list but present it in a sorted order, you can use the sorted() function. • The sorted() function lets you display your list in a particular order but doesn’t affect the actual order of the list.
- 36. PRINTING A LIST IN REVERSE ORDER What if you reverse again ?
- 37. AVOIDING INDEX ERRORS WHEN WORKING WITH LIST REMEMBER THAT INDEXING STARTS AT 0
- 39. FOR LOOP IN PYTHON AND USING LISTS