Implemented Features¶

Execution modes¶

REPL mode (cargo run)
Script mode (cargo run -- path/to/script.py)

Values and types¶

Numeric literals: integers (arbitrary precision), floats (1.0, 1e10, float('inf'))
String literals; True, False, None
Container literals: list [1, 2], tuple (1, 2), set {1, 2}, dict {"k": v}
Indexing for list, tuple, string, and dictionary (x[0], d["k"])
Slicing for lists and strings, including step slices (x[1:5], x[::2], x[::-1])

Operators¶

Arithmetic: + - * / // % ** @
Bitwise: & | ^ ~ << >>
Comparison: == != < <= > >=, chained comparisons, in, not in, is, is not
Boolean: and or not

Statements and control flow¶

Assignment forms: simple, unpacking, augmented (+= etc.), index/slice assignment, del
Statement sequencing with semicolons
if / elif / else, while [else], for ... in ... [else]
break, continue, pass, assert
global, nonlocal
raise, raise ... from ..., try / except / else / finally
with (context managers)
Comments with #

Functions¶

def name(args): ..., return
Positional arguments, trailing default arguments, keyword arguments
Keyword-only parameters (def f(a, *, b): ..., def f(*args, b): ...)
*args, **kwargs; call-site *args / **kwargs expansion
Lexical closures, decorators
lambda; ternary expressions

Classes¶

class Name: ..., single inheritance, __init__, instance attributes, bound methods
Decorators on class definitions
Special-method dispatch for @ / @=

Exception handling¶

Built-in exception classes: Exception, RuntimeError, TypeError, ValueError, AssertionError, IndexError, KeyError, StopIteration, RecursionError, SystemExit
Tuple exception clauses: except (TypeError, ValueError)

Imports¶

import module, from module import name [as alias], import module as alias, star imports
User .py file imports
Built-in modules: math (see below), sys (sys.exit, sys.argv, sys.path)

Built-in functions¶

Function	Notes
`print(*args, sep=" ", end="\n", file=None, flush=False)`
`len(x)`
`range(stop)` / `range(start, stop[, step])`
`abs(x)`
`min(iterable, *, key=None)` / `min(a, b, ..., key=None)`
`max(iterable, *, key=None)` / `max(a, b, ..., key=None)`
`sum(iterable, start=0)`
`enumerate(iterable, start=0)`
`zip(*iterables)`
`reversed(seq)`
`sorted(iterable, *, key=None, reverse=False)`
`isinstance(obj, classinfo)`	supports built-in types and user classes
`type(obj)`	returns a type object
`id(obj)`
`hasattr(obj, name)`
`getattr(obj, name[, default])`
`setattr(obj, name, value)`
`int(x)` / `int(x, base)`
`float(x)`
`str(x)`
`bool(x)`
`list(iterable)`
`tuple(iterable)`
`set(iterable)`
`dict(**kwargs)` / `dict(mapping)`

Built-in type methods¶

`list`¶

Method	Signature
`append`	`append(x)`
`pop`	`pop([i])`
`insert`	`insert(i, x)`
`extend`	`extend(iterable)`
`remove`	`remove(x)`
`clear`	`clear()`
`copy`	`copy()`
`reverse`	`reverse()`
`sort`	`sort(*, reverse=False)`
`index`	`index(x[, i[, j]])`
`count`	`count(x)`

`dict`¶

Method	Signature
`get`	`get(key[, default])`
`keys`	`keys()`
`values`	`values()`
`items`	`items()`
`update`	`update(other)`
`pop`	`pop(key[, default])`
`popitem`	`popitem()`
`setdefault`	`setdefault(key[, default])`
`clear`	`clear()`
`copy`	`copy()`

`str`¶

Method	Signature
`split`	`split([sep[, maxsplit]])`
`rsplit`	`rsplit([sep[, maxsplit]])`
`join`	`join(iterable)`
`strip`	`strip([chars])`
`lstrip`	`lstrip([chars])`
`rstrip`	`rstrip([chars])`
`upper`	`upper()`
`lower`	`lower()`
`capitalize`	`capitalize()`
`replace`	`replace(old, new[, count])`
`startswith`	`startswith(prefix)`
`endswith`	`endswith(suffix)`
`find`	`find(sub[, start[, end]])`
`rfind`	`rfind(sub[, start[, end]])`
`index`	`index(sub[, start[, end]])`
`rindex`	`rindex(sub[, start[, end]])`
`count`	`count(sub[, start[, end]])`
`isdigit`	`isdigit()`
`isalpha`	`isalpha()`
`isalnum`	`isalnum()`
`isspace`	`isspace()`

`tuple`¶

Method	Signature
`index`	`index(x[, i[, j]])`
`count`	`count(x)`

`math` module¶

Implemented¶

Name	Description
`pi`, `e`, `inf`, `nan`	Constants
`floor(x)`, `ceil(x)`	Floor / ceiling
`sqrt(x)`, `fabs(x)`	Square root, absolute value
`exp(x)`	eˣ
`log(x[, base])`, `log2(x)`, `log10(x)`	Logarithms
`pow(x, y)`	xʸ
`sin(x)`, `cos(x)`, `tan(x)`	Trigonometric
`asin(x)`, `acos(x)`, `atan(x)`, `atan2(y, x)`	Inverse trigonometric
`isnan(x)`, `isinf(x)`	Float classification

Not yet implemented¶

tau, degrees, radians, sinh, cosh, tanh, acosh, asinh, atanh, gcd, lcm, factorial, comb, perm, isqrt, trunc, fmod, modf, remainder, fsum, hypot, dist, isclose, isfinite, copysign, cbrt, exp2, expm1, log1p, erf, erfc, gamma, lgamma

Optimizer¶

PyRust applies a 15-pass peephole optimizer to every compiled function. See optimizer.md for a full description of each pass.