This guide explains str.endswith Method: Usage and Examples through a focused example and practical reasoning. No prior knowledge of this specific operation is required.
Understanding the Concept
str.endswith(suffix, start, end) tests whether the selected portion of a string ends with a suffix. The suffix can also be a tuple of strings, which is useful for checking several file extensions.
When You Would Use This
Check whether a filename is one of the accepted text formats.
Step-by-Step Example
filename = "notes.TXT"
normalized_filename = filename.lower()
print(normalized_filename.endswith(".txt"))
print(normalized_filename.endswith((".txt", ".md")))How the Example Works
Both checks return True. Normalizing the filename matters because suffix matching is case-sensitive. This is a filename test, not proof that the file content is safe or valid.
Example Output
True
TrueTry It Yourself
Accept .csv and .tsv filename suffixes using a single call.
Common Beginner Mistakes
- Forgetting that the comparison is case-sensitive.
- Treating a filename extension as a reliable security or content-type check.
- Assuming
endswith()removes the suffix from the string.
Key Takeaways
str.endswith(suffix, start, end)tests whether the selected portion of a string ends with a suffix.- Both checks return
True. - Avoid this mistake: Forgetting that the comparison is case-sensitive.