Lists are one of the important python data structure widely used for solving numerical, statistical problems. Lists are more like arrays in other programming languages, But lists are a heterogeneous data structure, List is defined with items separated by the comma  (\u201c,\u201d ) and enclosed by square brackets (\u2018[]\u2018)<\/p>\n

This below example using Jupyter notebook shows creating python list.  In Jupyter notebook, the output of each line is given immediately after the line.<\/p>\n

Creating List in Python:<\/strong><\/p>\n

In the given example we are creating list_ex <\/em><\/strong>which is a list of numbers, other list list2<\/em> <\/strong>which is a list of alphabets, the other list list_hetro<\/em><\/strong> is a heterogeneous list which contains numbers, alphabets, and strings as list items. Python len() <\/strong>function is used to get the length of the list which indicates no of elements present in the list.<\/p>\n

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Accessing elements of lists and update List values in Python:<\/strong><\/p>\n

List elements in the python lists can be accessed using the index. List index starts from zero and the index of the final element of the list is N-1 (N = length of the list).<\/p>\n

list_ex[0]  gives the first element of the list.<\/p>\n

list_hetro[3] gives the 4^{th<\/sup> element of the list which is \u201cconcept\u201d.<\/em><\/strong><\/p>\n}

Similarly to update the values in this list we can use indexing for updating.<\/p>\n

list_hetro[3] = “c2plabs.com”  <\/strong>This statement updates 4^{th<\/sup> element of list to \u201cc2plabs.com\u201d. <\/strong>Updated list can be seen by printing the list.<\/p>\n}

Deleting list element:<\/strong><\/p>\n

List elements can be deleted using the index, an example to delete 5^{th<\/sup> Element list_hetro <\/strong><\/p>\n}

del list_hetro[5]    <\/strong># This statement deletes element \u201cprototype\u201d from the list.<\/p>\n

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Slice Operator [:] and Slicing of List in Python:<\/strong><\/p>\n

Slice Operator [:] is used to extract a single element or ranges of elements from the list.<\/p>\n

The syntax of slice operator is list_name [start_index : end_index]<\/strong><\/p>\n

Ex:  new_list=list_hetro [1:3]  <\/strong>#In this statement start index is 1 and end index is 3, in slicing operation end index is excluded.<\/p>\n

Above statement create new list form list_hetro element from index \u201c1\u201d to index \u201c2\u201d excluding end index which is 3 here.<\/p>\n

To get the final or last element of the list end index is \u201c-1\u201d.  <\/strong>Given example shows how to use slice operator to access list items.<\/p>\n

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Python Built-in functions:<\/strong><\/p>\n

Python offers built-in functions to work on lists.<\/p>\n

Len (list) : <\/strong>Length of the list, No of elements present in the list.<\/p>\n

Max(list) : <\/strong>This function returns maximum value present in the list.<\/p>\n

Min(list) : <\/strong>This function return minimum value present in the list.<\/p>\n

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List methods:<\/strong><\/p>\n

Python lists have methods to perform different operations on the list like<\/p>\n

list.append (object) :<\/strong> This method appends new object to list<\/p>\n

list.count (object):<\/strong> This method returns the count of  occurrence of the object in the given list<\/p>\n

list.remove(object):<\/strong> This method removes the first occurrence of the object from the list<\/p>\n

list.insert (index, object):<\/strong> This method inserts the object at a index specified.<\/p>\n

In the below given example we are defining list_new as<\/p>\n

list_new = [“c2plabs.com”, “concept”, 2, “prototype”]<\/p>\n

New elements “Machine”, “Learning”, “c2plabs.com” are added to list using append method.<\/p>\n

This example also shows counting no of occurrences of “c2plabs.com” using list.count() method.<\/p>\n

<\/p>\n

This example also shows the usage of list methods like list.remove() and list.insert.<\/p>\n","protected":false},"excerpt":{"rendered":"

Lists are one of the important python data structure widely used for solving numerical, statistical problems. Lists are more like arrays in other programming languages, But lists are a heterogeneous data structure, List is defined with items separated by the comma  (\u201c,\u201d ) and enclosed by square brackets (\u2018[]\u2018) This below example using Jupyter notebook shows […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[85],"tags":[74,73],"class_list":["post-382","post","type-post","status-publish","format-standard","hentry","category-python","tag-python-basics","tag-python-lists"],"yoast_head":"\n