str.endswith()

str.endswith(suffix[, start[, end]])

Returns: bool · Updated March 13, 2026 · String Methods

strings checking suffix

The .endswith() method checks whether a string ends with a specified substring or one of several possible suffixes. It returns a boolean value, making it useful for conditional logic in file handling, validation, and text processing.

Syntax

str.endswith(suffix[, start[, end]])

Parameters

Parameter	Type	Default	Description
`suffix`	`str` or `tuple`	—	The substring or tuple of substrings to check for at the end of the string
`start`	`int`	`0`	Starting position for the search
`end`	`int`	`len(string)`	Ending position for the search

Returns: bool — True if the string ends with the suffix, False otherwise.

Examples

Basic usage

text = "hello.txt"
print(text.endswith(".txt"))
# True

print(text.endswith(".pdf"))
# False

Checking multiple suffixes

filename = "document.pdf"

# Check against multiple extensions
if filename.endswith((".pdf", ".doc", ".docx")):
    print("This is a document file")
# This is a document file

This is useful when you need to check a file against multiple allowed extensions.

Using start and end parameters

url = "https://example.com/page"

# Check only the domain portion
print(url.startswith("https", 0, 8))
# True

# Check last 4 characters
print(url.endswith(".com"))  # False

The start and end parameters let you check a specific slice of the string without creating a substring first.

Practical file handling example

import os

files = ["report.pdf", "data.csv", "image.png", "script.py", "readme.txt"]

for f in files:
    if f.endswith((".pdf", ".txt")):
        print(f"Found document: {f}")
# Found document: report.pdf
# Found document: readme.txt

Common Patterns

Validating file extensions

def allowed_file(filename, allowed_extensions):
    return any(filename.endswith(ext) for ext in allowed_extensions)

print(allowed_file("photo.jpg", [".jpg", ".png", ".gif"]))
# True

print(allowed_file("photo.exe", [".jpg", ".png", ".gif"]))
# False

Checking string completions

questions = [
    "What is Python?",
    "How do you install Python?",
    "Why use Python?",
    "When was Python created?"
]

# Find questions starting with "How" or "What"
for q in questions:
    if q.startswith(("How", "What")):
        print(f"Question word: {q.split()[0]}")
# Question word: What
# Question word: How

Using with path handling

filepath = "/home/user/documents/report.pdf"

# Check file extension
print(filepath.endswith(".pdf"))
# True

# Check for multiple possible extensions
print(filepath.endswith((".pdf", ".docx", ".xlsx")))
# True

Errors

.endswith() accepts a tuple of suffixes. Passing any other non-string iterable (like a list) raises a TypeError:

# This works - tuple is accepted
"file.txt".endswith(["txt", "pdf"])
# TypeError: endswith first arg must be str or tuple

# Correct usage with tuple
"file.txt".endswith(("txt", "pdf"))
# True