{"id":341,"date":"2020-10-07T04:13:13","date_gmt":"2020-10-07T04:13:13","guid":{"rendered":"https:\/\/www.pythontutorial.net\/?page_id=341"},"modified":"2025-03-26T13:53:38","modified_gmt":"2025-03-26T13:53:38","slug":"python-find-index-of-element-in-list","status":"publish","type":"page","link":"https:\/\/www.pythontutorial.net\/python-basics\/python-find-index-of-element-in-list\/","title":{"rendered":"How to Find the Index of an Element in a List"},"content":{"rendered":"\n

Summary<\/strong>: in this tutorial, you’ll learn how to find the index of an element in a list.<\/p>\n\n\n\n

To find the index of an element in a list, you use the index()<\/code> function. <\/p>\n\n\n\n

The following example defines a list of cities and uses the index()<\/code> method to get the index of the element whose value is 'Mumbai'<\/code>:<\/p>\n\n\n

cities = ['New York'<\/span>, 'Beijing'<\/span>, 'Cairo'<\/span>, 'Mumbai'<\/span>, 'Mexico'<\/span>]\n\nresult = cities.index('Mumbai'<\/span>)\nprint(result)\n<\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\n\n\n
Try it<\/a><\/p>\n\n\n\n
Output:<\/p>\n\n\n
3<\/code><\/span><\/pre>\n\n\n
It returns 3 as expected.<\/p>\n\n\n\n
However, if you attempt to find an element that doesn’t exist in the list using the index()<\/code> function, you’ll get an error. <\/p>\n\n\n\n
This example uses the index()<\/code> function to find the Osaka<\/code> city in the cities<\/code> list:<\/p>\n\n\n
cities = ['New York'<\/span>, 'Beijing'<\/span>, 'Cairo'<\/span>, 'Mumbai'<\/span>, 'Mexico'<\/span>]\n\nresult = cities.index('Osaka'<\/span>)\nprint(result)<\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\n\n\n
Error:<\/p>\n\n\n
ValueError: 'Osaka'<\/span> is<\/span> not<\/span> in<\/span> list<\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\n\n\n
To fix this issue, you need to use the in<\/code> operator. <\/p>\n\n\n\n
The in<\/code> operator returns True<\/code> if a value is in the list. Otherwise, it returns False<\/code>.<\/p>\n\n\n\n
Before using the index()<\/code> function, you can use the in<\/code> operator to check if the element that you want to find is in the list. For example:<\/p>\n\n\n
cities = ['New York'<\/span>, 'Beijing'<\/span>, 'Cairo'<\/span>, 'Mumbai'<\/span>, 'Mexico'<\/span>]\ncity = 'Osaka'<\/span>\n\nif<\/span> city in<\/span> cities:\n    result = cities.index(city)\n    print(f\"The {city}<\/span> has an index of {result}<\/span>.\"<\/span>)\nelse<\/span>:\n    print(f\"{city}<\/span> doesn't exist in the list.\"<\/span>)\n<\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\n\n\n
Output:<\/p>\n\n\n
Osaka doesn't exist in the list.<\/span><\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\n\n\n
Summary #<\/a><\/h2>\n\n\n\n
Try it<\/a><\/p>\n\n\n\n
Try it<\/a><\/p>\n\n\n\n