String manipulation

Enables explicit, readable suffix matching without manual slice arithmetic.

File I/O: validating uploaded filenames by extension Web scraping: filtering URLs by path suffix CLI tools: branching on user-supplied flag format

Data processing scripts Web applications handling uploads General Python codebases

string_variable.endswith(suffix)

... .endswith(...)

string_variable: str, suffix: str or tuple of str

• startswith
• find
• rsplit
• regex

• string_variable[-len(suffix):] == suffix
• re.search(r'suffix$'
• string_variable)

Assuming case-insensitivity (cause: expecting .endswith to mirror SQL LIKE; consequence: '.TXT' files silently skipped) — use .lower().endswith() instead; Passing a list instead of a tuple (cause: overlooking the type restriction; consequence: TypeError at runtime); Forgetting empty suffix always returns True (cause: not reading docs; consequence: conditional branch entered unintentionally)

startswith — checks prefix instead of suffix; 'in' operator — checks substring anywhere, not just at the end; re.search with $ anchor — supports complex pattern matching but is slower

Coming from Java: .endsWith() is similar; coming from JavaScript: .endsWith() exists but syntax differs.

• startswith
• find
• rsplit
• regex

Avoid when you need case-insensitive matching — .endswith is strictly case-sensitive, so pair with .lower(). For very hot loops on large data, tuple-of-suffixes is faster than chained or-calls. Passing start/end arguments limits the search region but is rarely needed and can confuse readers.

Makes suffix checks explicit and readable, avoiding error‑prone manual slicing.

Think of .endswith() as checking if a book ends with a specific chapter title — if the final pages match, you know it's the right volume.

The argument can be a single string or a tuple of strings.

re.search(r'{suffix}$', string_variable)