pytclsh 0.0.2

pytclsh: Pure Python TCL interpreter

pytcl

Pure Python TCL interpreter and parser library.

Installation

pip install pytcl

Usage

Interpreter

from pytcl.interpreter import Interpreter

i = Interpreter()
i.substitute_string("set x 42")         # "42"
i.substitute_string("expr {$x * 2}")    # "84"
i.substitute_string("set x")            # "84"

Evaluate a .tcl file:

from pathlib import Path
from pytcl.interpreter import Interpreter

i = Interpreter()
i.substitute_file(Path("script.tcl"))

Custom commands

Commands are plain callables stored in the namespace:

from pytcl.interpreter import Interpreter

i = Interpreter()
i.namespace["double"] = lambda args, ns: str(int(args[0]) * 2)
i.substitute_string("double 21")  # "42"

Parser

Parse Tcl source into a typed tree without executing it:

from pytcl.words import TCLScript

script = TCLScript.read(iter("set x [expr {1 + 2}]"))
for command in script.commands:
    print(command.name, command.args)

Built-in commands

set, unset, expr, if / elseif / else, while, foreach, proc, return, break, continue, incr, append, puts, error

Development

uv sync --all-extras        # install dependencies
uv run pytest               # unit tests
uv run pytest integrations/ # integration tests (requires Docker)
uv run ruff check .         # lint
uv run pre-commit run --all-files