dict_test = """ for i in range(1000): x = d.get(i, 0) """
print(f"Fibonacci(n) = result") print(f"Normal: normal_time:.3fs") print(f"Cached: cached_time:.3fs") class Point: slots = ('x', 'y') # Even faster in 3.13
from typing import assert_never, TypeIs, Literal def is_string_list(obj: object) -> TypeIs[list[str]]: """More precise type guard than TypeGuard""" return isinstance(obj, list) and all(isinstance(item, str) for item in obj) python 3.13 changes
def benchmark_fibonacci(): n = 35
src.write_text("Hello, Python 3.13!") # Copy with metadata preservation src.copy(dst, preserve_metadata=True) print(f"Copied: dst.read_text()") # Move (replaces shutil.move) new_location = Path(tmpdir) / "moved.txt" src.move(new_location) print(f"Source exists: src.exists()") # False print(f"Moved to: new_location.read_text()") Better type narrowing and more precise type checking. dict_test = """ for i in range(1000): x = d
def process_data(data: list[str] | list[int]): if is_string_list(data): # Type checker knows data is list[str] here print(f"String list: ', '.join(data)") else: # Type checker knows data is list[int] here print(f"Sum of ints: sum(data)") def handle_status(status: Literal["active", "inactive", "pending"]) -> str: match status: case "active": return "User is active" case "inactive": return "User is inactive" case "pending": return "User pending approval" case _: assert_never(status) # Type checker verifies all cases handled 6. Performance Improvements Python 3.13 includes a new JIT compiler (experimental) and optimized internals.
# Check for removed features checks = [ ("crypt", "Module 'crypt' removed in 3.13"), ("2to3", "Tool removed in 3.13"), ] # Check for removed features checks = [
if sys.version_info < (3, 13): warnings.warn("Not running on Python 3.13", RuntimeWarning) return