The endswith() method returns True if a string ends with a specified suffix, and False otherwise. It is one of the most practical string methods for checking file extensions, validating URL endings, and writing clean conditional logic without manual string slicing.
Test how a string ends.
True or False result.
Match any of several endings.
Search within a slice.
Check .txt, .pdf, .jpg.
End vs beginning checks.
In Python, endswith() is a built-in string method that checks whether the string’s ending matches a given suffix. For example, "document.txt".endswith(".txt") returns True, while "document.pdf".endswith(".txt") returns False. You can pass a tuple of suffixes to match any one of several endings in a single call.
Prefer endswith() over slicing like s[-4:] == ".txt". It is more readable, handles edge cases safely, and supports checking multiple suffixes with a tuple.
The endswith() method accepts one required and two optional parameters:
string.endswith(suffix, start, end)suffix — a string or tuple of strings to check at the end (required).start — optional start index; the check runs on string[start:end].end — optional end index; search stops before this position.True or False; the original string is not modified."A" and "a" are treated as different characters.| Expression | Result |
|---|---|
"hello.py".endswith(".py") | True |
"hello.py".endswith(".txt") | False |
"photo.jpg".endswith((".jpg", ".png")) | True |
"File.TXT".endswith(".txt") | False (case-sensitive) |
"abcdef".endswith("ef", 0, 5) | False (slice ends at "e") |
name.endswith(".csv")Single suffix check
name.endswith((".jpg", ".png"))Any suffix matches
text.endswith("ing", 0, 7)Check within range
not url.endswith("/")When suffix is absent
Run these examples in any Python 3 interpreter. Each one shows a common suffix-checking pattern.
Check whether a filename ends with a specific extension.
Verify that a file is a text file by checking its extension.
filename = "document.txt"
is_text = filename.endswith(".txt")
print(f"File: {filename}")
print(f"Is text file: {is_text}")endswith(".txt") compares the last four characters of the string.True because "document.txt" ends with ".txt".Pass a tuple to match any of several image extensions in one call.
filename = "photo.jpg"
image_exts = (".jpg", ".jpeg", ".png", ".gif")
is_image = filename.endswith(image_exts)
print(f"{filename} is an image: {is_image}")Python checks each suffix in the tuple and returns True if any one matches. This is cleaner than chaining multiple or conditions.
Slice boundaries, case rules, and comparison with startswith().
Check whether a portion of the string ends with a suffix.
text = "running fast"
full = text.endswith("ing")
partial = text.endswith("ing", 0, 7)
print("Full string: ", full)
print("First 7 chars:", partial)text[0:7] is "running", which ends with "ing". The full string ends with "fast", so the full check returns False.
endswith() treats uppercase and lowercase as different.
filename = "Report.PDF"
print("Strict: ", filename.endswith(".pdf"))
print("Insensitive:", filename.lower().endswith(".pdf"))Call .lower() on the filename (and use a lowercase suffix) when you want extension checks to ignore case differences.
Use the right method for prefixes vs suffixes—including proper URL checks.
url = "https://example.com/page"
path = "/path/to/report.pdf"
print("URL uses HTTPS: ", url.startswith("https://"))
print("URL ends with .com:", url.endswith(".com"))
print("Path is PDF: ", path.endswith(".pdf"))startswith("https://") checks the URL prefix—the correct way to verify HTTPS.url.endswith(".com") is False here because the URL ends with "/page", not ".com".endswith(".pdf") correctly identifies the file extension in the path..csv, .json, or image files in upload handlers."/" or specific path segments.endswith() WorksIf start and end are given, the check runs on that slice; otherwise the full string is used.
Python checks whether the final characters of the range match the suffix (or any suffix in a tuple).
No new string is created—only a boolean answer for your if statement or filter.
Readable suffix checks without manual index math or string slicing.
endswith() is case-sensitive—normalize with .lower() when comparing file extensions."" always returns True (every string ends with an empty string).re module instead.endswith("s") to check HTTPS—use startswith("https://") instead.The endswith() method is a simple, readable way to test string endings in Python. Whether you are filtering files by extension, validating paths, or writing conditional logic, it gives you a clear boolean answer in one expression.
Remember: pass a tuple for multiple suffixes, use startswith() for prefixes, and call .lower() when case should not matter.
".pdf" not "pdf".lower() for case-insensitive extension checksendswith() over manual slicingstartswith() for URL schemes and path prefixesendswith("s") to detect HTTPS URLsendswith() for regex-style pattern matchingendswith(".com") fails when the URL has a path after the domainbool, not a string or indexendswith()Use these points when checking string endings in Python.
True or False only.
Purpose.txt, .pdf, .jpg.
Use caseMatch any in one call.
Syntaxstart and end optional.
AdvancedUse lower() if needed.
Edge caseContinue with expandtabs(), find(), and the rest of the string method reference.
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