Expression interpreter written in Python

Related tags

Miscellaneouspythoncalculatorinterpreterpython3
Overview

Calc Interpreter

Python Package other branches Python Version Python Implementation

An interpreter modeled after a calculator implemented in Python 3. The program currently only supports basic mathematical expressions. The package uses Reverse Polish Notation also known as postfix expression internally to easily represent mathematical expressions. This is powerful as it allows operators to be organised in such a way that precedence is absolute meaning an operator that is encountered first will always be executed first.

However, it is obvious that postfix is not normal or rather not usually taught in schools and thus infix expression is still the way for the user to write expressions. The interpreter uses a modified Shunting-Yard algorithm to produce Abstract Syntax Trees. Evaluation of ASTs is trivial, and they are flexible making it easy to extend the grammar and functionality later on.

Installation

The package is available in PyPI and can be installed via pip.

pip install expr-calc
#or
python3 -m pip install expr-calc

Usage

The best way to run the program currently is to execute the REPL and can be done in a python file or through your terminal.

Assuming your present working directory is inside the cloned repo, you can run the following command without the comment.

# inside /clone_path/expr_calc/
python -m expr_calc

The test suite can also be ran with pytest when inside the cloned repo

pytest  # or python -m pytest

Example

Once inside the REPL, you can start evaluating expressions. Currently, only operators listed in Features are supported.

calc> 1 + 1
2

calc> 345--500
845

calc> -2
-2

calc> 123 ^ 4
228886641

calc> 32 / 1.5
21.33333333333333333333333333

calc> 123 * 456
56088

calc> 34 % 5
4

calc> 4 ^ 1/2
0.5

calc> 4 ^ (1/2)
2.0

Features

  • Infix expressions
  • Basic operators such as +, -, *, /, %, ^
  • Tokens created from an expression can also be fetched to be manipulated if one wanted to do so
  • Expressions are transformed into m-ary Tree objects connected to each other

Features I want to add later

  • variable support
  • custom functions
  • more mathematical functions such as sin, cos, tan, etc
  • and possibly a simple symbolic computation support

Resources

You might also like...
Structural basis for solubility in protein expression systems

Structural basis for solubility in protein expression systems Large-scale protein production for biotechnology and biopharmaceutical applications rely

ProteinQure 16 Aug 18, 2022
PyDy, short for Python Dynamics, is a tool kit written in the Python
PyDy, short for Python Dynamics, is a tool kit written in the Python

PyDy, short for Python Dynamics, is a tool kit written in the Python programming language that utilizes an array of scientific programs to enable the study of multibody dynamics. The goal is to have a modular framework and eventually a physics abstraction layer which utilizes a variety of backends that can provide the user with their desired workflow

PyDy 307 Jan 1, 2023
Simple, high-school-leveled sequence library written in Python / 간단한 고등학교 수준 수열 라이브러리 (Python)
Simple, high-school-leveled sequence library written in Python / 간단한 고등학교 수준 수열 라이브러리 (Python)

Simple, high-school-leveled sequence library written in Python

Sanha 1 Dec 8, 2021
Msgpack serialization/deserialization library for Python, written in Rust using PyO3 and rust-msgpack. Reboot of orjson. msgpack.org[Python]

ormsgpack ormsgpack is a fast msgpack library for Python. It is a fork/reboot of orjson It serializes faster than msgpack-python and deserializes a bi

Aviram Hassan 139 Dec 30, 2022
Synthetik Python Mod - A save editor tool for the game Synthetik written in python

Synthetik_Python_Mod A save editor tool for the game Synthetik written in python

null 2 Sep 10, 2022
MiniJVM is simple java virtual machine written by python language, it can load class file from file system and run it.

MiniJVM MiniJVM是一款使用python编写的简易JVM，能够从本地加载class文件并且执行绝大多数指令。 支持的功能 1.从本地磁盘加载class并解析 2.支持绝大多数指令集的执行 3.支持虚拟机内存分区以及对象的创建 4.支持方法的调用和参数传递 5.支持静态代码块的初始化 不支

keguoyu 60 Apr 1, 2022
Pygments is a generic syntax highlighter written in Python

Welcome to Pygments This is the source of Pygments. It is a generic syntax highlighter written in Python that supports over 500 languages and text for

null 1.2k Jan 6, 2023
Retrying is an Apache 2.0 licensed general-purpose retrying library, written in Python, to simplify the task of adding retry behavior to just about anything.

Retrying Retrying is an Apache 2.0 licensed general-purpose retrying library, written in Python, to simplify the task of adding retry behavior to just

Ray Holder 1.9k Dec 29, 2022
A full-featured, hackable tiling window manager written and configured in Python
A full-featured, hackable tiling window manager written and configured in Python

A full-featured, hackable tiling window manager written and configured in Python Features Simple, small and extensible. It's easy to write your own la

Qtile 3.8k Dec 31, 2022
Comments
  • Better lexing(and scanning) and parsing

    Better lexing(and scanning) and parsing

    There is currently an issue with the lexing strategy for unary operators. Because i have only partially implemented it, constructs that uses unary operators are note exactly recognised. For example

    > -(1)
1  # should be -1

    This is problematic because it affects expressions such as to give wrong the answer

    > -1^2
1  # should be -1
> -(1^2)
1  # should be -1

    The main reason for this is that unary operators are not actually lexed themselves, when an expression such as -1 is passed, the program checks if the immediately succeeding character is a number and immediately binds the sign to the number after it, a bracket/parentheses is not a number and thus the operator doesn't get lexed independently at all disabling the parser to not recognise have any knowledge of it.

    Also note that + and - are always initially tokenised as Token.BINARY_OPs and I believe this should change.

    see this line

    bug enhancement 
    opened by lestherll 2
  • Support for high precision floating-points

    Support for high precision floating-points

    Currently, the interpreter uses raw Python as the engine for evaluating mathematical expressions. This is good in normal cases but as you may already know, computers aren't so good at dealing with high precision floating-points. It would be good to be able to utilise perhaps some module to deal with this.

    > 9.999999800000001 * 10^15
9999999800000002.0   # should be 9999999800000001
    bug enhancement 
    opened by lestherll 0
  • Create custom error codes

    Create custom error codes

    Currently, there are no custom error codes. Adding one would make the project more concrete and robust.

    Example

    # inside REPL
> 1.1.1
SyntaxError: Numbers can only have one decimal point
    enhancement 
    opened by lestherll 0
Releases(v0.1.2)
Owner
BSc Comp Sci at Newcastle University
GitHub Repository
This directory gathers the tools developed by the Data Sourcing Working Group

BigScience Data Sourcing Code This directory gathers the tools developed by the Data Sourcing Working Group First Sourcing Sprint: October 2021 The co

BigScience Workshop 27 Nov 04, 2022
Platform Tree for Xiaomi Redmi Note 7/7S (lavender)

The Xiaomi Redmi Note 7 (codenamed "lavender") is a mid-range smartphone from Xiaomi announced in January 2019. Device specifications Device Xiaomi Re

MUHAMAD KHOIRON 2 Dec 20, 2021
Used the pyautogui library to automate some processes on the computer

Pyautogui Utilizei a biblioteca pyautogui para automatizar alguns processos no c

Dheovani Xavier 1 Dec 30, 2021
Synchrosqueezing, wavelet transforms, and time-frequency analysis in Python

Synchrosqueezing is a powerful reassignment method that focuses time-frequency representations, and allows extraction of instantaneous amplitudes and frequencies

John Muradeli 382 Jan 06, 2023
MuMMI Core is the underlying infrastructure and generalizable component of the MuMMI framework

MuMMI Core is the underlying infrastructure and generalizable component of the MuMMI framework, which facilitates the coordination of massively parallel multiscale simulations.

4 Aug 17, 2022
Criando um jogo de naves espaciais com Pygame. Para iniciantes em Python

Curso de Programação de Jogos com Pygame Criando um jogo de naves espaciais com Pygame. Para iniciantes em Python Pré-requisitos Antes de começar este

Flávio Codeço Coelho 33 Dec 02, 2022
Gaia: a chrome extension that curates environmental news of a company

Gaia - Gaia: Your Environment News Curator Call for Code 2021 Gaia: a chrome extension that curates environmental news of a company Explore the docs »

4 Mar 19, 2022
Scripts to integrate DFIR-IRIS, MISP and TimeSketch

Scripts to integrate DFIR-IRIS, MISP and TimeSketch

Koen Van Impe 20 Dec 16, 2022
Open source book about making Python packages.

Python packages Tomas Beuzen & Tiffany Timbers Python packages are a core element of the Python programming language and are how you create organized,

Python Packages 169 Jan 06, 2023
Insert a Spotify Playlist, Get a list of YouTube URLs from it.

spotbee This is a module that spits out YouTube URLs from Spotify Playlist URLs Why use this? It is asynchronous which makes it compatible to use with

Nishant Sapkota 10 Apr 06, 2022
Python Multilingual Ucrel Semantic Analysis System

PymUSAS Python Multilingual Ucrel Semantic Analysis System, it currently is a rule based token level semantic tagger which can be added to any spaCy p

UCREL 13 Nov 18, 2022
Python AVL Protocols Server for Codec 8 and Codec 8 Extended Protocols

pycodecs Package provides python AVL Protocols Server for Codec 8 and Codec 8 Extended Protocols This package will parse the AVL Data and log it in hu

Vardharajulu K N 2 Jun 21, 2022
This alerts you when the avalanche score a goal

This alerts you when the avalanche score a goal

Davis Burrill 1 Jan 15, 2022
A numbers check python package

A numbers check python package

Fayas Noushad 3 Nov 28, 2021
NCAR/UCAR virtual Python Tutorial Seminar Series lesson on MetPy.

The Project Pythia Python Tutorial Seminar Series continues with a lesson on MetPy on Wednesday, 2 February 2022 at 1 PM Mountain Standard Time.

Project Pythia Tutorials 6 Oct 09, 2022
Blender 3.1 Alpha (and later) PLY importer that correctly loads point clouds (and all PLY models as point clouds)

import-ply-as-verts Blender 3.1 Alpha (and later) PLY importer that correctly loads point clouds (and all PLY models as point clouds) Latest News Mand

Michael Prostka 82 Dec 20, 2022
Age of Empires II recorded game parsing and summarization in Python 3.

mgz Age of Empires II recorded game parsing and summarization in Python 3. Supported Versions Age of Kings (.mgl) The Conquerors (.mgx) Userpatch 1.4

148 Dec 11, 2022
Originally used during Marketplace.tf's open period, this program was used to get the profit of items bought with keys and sold for dollars.

Originally used during Marketplace.tf's open period, this program was used to get the profit of items bought with keys and sold for dollars. Practically useless for me now, but can be used as an exam

BoggoTV 1 Dec 11, 2021
[draft] tools for schnetpack

schnetkit some tooling for schnetpack EXPERIMENTAL/IN DEVELOPMENT DO NOT USE This is an early draft of some infrastructure built around schnetpack. In

Marcel 1 Nov 08, 2021
Basic-Killfeed - A simple DayZ Console Killfeed

Basic-Killfeed A simple DayZ Console Killfeed. Setup Install Python Version 3.10

Nick 1 Apr 25, 2022