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# Python3.x Python3 Lists Sequences are the most fundamental data structures in Python. Each value in a sequence has a corresponding position value, called an index. The first index is 0, the second index is 1, and so on. Python has 6 built-in sequence types, but the most common are lists and tuples. Operations that can be performed on lists include indexing, slicing, concatenation, repetition, and membership checking. Additionally, Python has built-in methods to determine the length of a sequence and to find the maximum and minimum elements. Lists are the most commonly used Python data type. They can be represented as comma-separated values within square brackets. The data items in a list do not need to be of the same type. To create a list, simply enclose comma-separated different data items in square brackets, as shown below: list1 =['Google','',1997,2000] list2 =[1,2,3,4,5] list3 =["a","b","c","d"] list4 =['red','green','blue','yellow','white','black'] * * * ## Accessing List Values Similar to string indexing, list indexing starts from 0, the second index is 1, and so on. Lists can be sliced, concatenated, etc., using their indices. !(#) ## Example #!/usr/bin/python3 list=['red','green','blue','yellow','white','black'] print(list) print(list) print(list) The output of the above example is: red green blue Indexing can also start from the end. The index of the last element is -1, the one before that is -2, and so on. !(#) ## Example #!/usr/bin/python3 list=['red','green','blue','yellow','white','black'] print(list) print(list) print(list) The output of the above example is: black white yellow You can also use square brackets [] for slicing to access values in the list, as shown below: !(#) ## Example #!/usr/bin/python3 nums =[10,20,30,40,50,60,70,80,90] print(nums[0:4]) The output of the above example is: [10, 20, 30, 40] Slicing using negative index values: ## Example #!/usr/bin/python3 list=['Google','',"Zhihu","Taobao","Wiki"] # Read the second element print("list: ",list) # Slice from the second element (inclusive) to the second-to-last element (exclusive) print("list[1:-2]: ",list[1:-2]) The output of the above example is: list: list[1:-2]: ['', 'Zhihu'] * * * ## Updating Lists You can modify or update the data items in a list. You can also use the append() method to add list items, as shown below: ## Example (Python 3.0+) #!/usr/bin/python3 list=['Google','',1997,2000] print("The third element is: ",list) list=2001 print("The updated third element is: ",list) list1 =['Google','','Taobao'] list1.append('Baidu') print("Updated list: ", list1) **Note:** We will discuss the usage of the [append()](#) method in the following chapters. The output of the above example is: The third element is: 1997 The updated third element is: 2001 Updated list: ['Google', '', 'Taobao', 'Baidu'] * * * ## Deleting List Elements You can use the del statement to delete elements from a list, as shown in the following example: ## Example (Python 3.0+) #!/usr/bin/python3 list=['Google','',1997,2000] print("Original list: ",list) del list