startswith, endswith ExamplesUse the startswith and endswith methods to test the beginning and end of strings.
This page was last reviewed on Sep 25, 2022.
Startswith, endswith. All things have a start and an end. Often we need to test the starts and ends of strings. We use the startswith and endswith methods.
Some notes. We can take a substring and compare that to a string—this can do the same thing as startswith or endswith. But with specialized methods, our code is clearer and likely faster.
Example, startswith. Here we have a string that has many characters in it. We want to see what its prefix may match. We use 3 if-statements.
Next We use startswith on an example string. We use "not startswith" to see if the string does not start with "elephant."
phrase = "cat, dog and bird" # See if the phrase starts with these strings. if phrase.startswith("cat"): print(True) if phrase.startswith("cat, dog"): print(True) # It does not start with this string. if not phrase.startswith("elephant"): print(False)
True True False
Example, endswith. Here we use the endswith method. It uses the same syntax as startswith but tests the final characters in a string. We test a URL's domain with it.
url = "https://www.dotnetperls.com/" # Test the end of the url. if url.endswith("/"): print("Ends with slash") if url.endswith(".com/"): print("Ends with .com/") if url.endswith("?") == False: # Does not end in a question mark. print(False)
Ends with slash Ends with .com/ False
Some notes, performance. In my performance testing, I have found Python tends to be fastest when the minimal number of statements and method calls are made.
So Startswith and endswith are a good choice—they can keep program short and clear.
A summary. With string-testing methods like startswith and endswith, we can check the beginning and ends of strings. This can avoid complexity in code.
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Sam Allen is passionate about computer languages. In the past, his work has been recommended by Apple and Microsoft and he has studied computers at a selective university in the United States.
This page was last updated on Sep 25, 2022 (edit).
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