Native string operations

These str operations have fast, optimized implementations. Other string operations use generic implementations that are often slower.

Construction

• String literal

• str(x: int)

• str(x: object)

• repr(x: int)

• repr(x: object)

Operators

• Concatenation (s1 + s2)

• Indexing (s[n])

• Slicing (s[n:m], s[n:], s[:m])

• Comparisons (==, !=)

• Augmented assignment (s1 += s2)

• Containment (s1 in s2)

Methods

• s.encode()

• s.encode(encoding: str)

• s.encode(encoding: str, errors: str)

• s1.endswith(s2: str)

• s1.endswith(t: tuple[str, ...])

• s1.find(s2: str)

• s1.find(s2: str, start: int)

• s1.find(s2: str, start: int, end: int)

• s.join(x: Iterable)

• s.lstrip()

• s.lstrip(chars: str)

• s.partition(sep: str)

• s.removeprefix(prefix: str)

• s.removesuffix(suffix: str)

• s.replace(old: str, new: str)

• s.replace(old: str, new: str, count: int)

• s1.rfind(s2: str)

• s1.rfind(s2: str, start: int)

• s1.rfind(s2: str, start: int, end: int)

• s.rpartition(sep: str)

• s.rsplit()

• s.rsplit(sep: str)

• s.rsplit(sep: str, maxsplit: int)

• s.rstrip()

• s.rstrip(chars: str)

• s.split()

• s.split(sep: str)

• s.split(sep: str, maxsplit: int)

• s.splitlines()

• s.splitlines(keepends: bool)

• s1.startswith(s2: str)

• s1.startswith(t: tuple[str, ...])

• s.strip()

• s.strip(chars: str)

Note

bytes.decode() is also optimized.

Formatting

A subset of these common string formatting expressions are optimized:

• F-strings

• "...".format(...)

• "..." % (...)

Functions

• len(s: str)

• ord(s: str)