Python startswith, endswith Examples

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.Strings

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."

Python program that uses startswith 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) Output 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.

Python program that uses endswith 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) Output Ends with slash Ends with .com/ False

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.

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.