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
You'll learn about Iterators, Generators, Closure, Decorators, Property, and RegEx in detail with examples.

07_Python_Advanced_Topics Introduction 👋 In this tutorial, you will learn about: Python Iterators: They are objects that can be iterated upon. In thi

Milaan Parmar / Милан пармар / _米兰 帕尔马 252 Dec 23, 2022
Click2call for asterisk with python

Click2call para Asterisk com Python Este projeto disponibiliza uma API construíd

Benedito Marques 1 Jan 17, 2022
sawa (ꦱꦮ) is an open source programming language, an interpreter to be precise, where you can write python code using javanese character.

ꦱꦮ sawa (ꦱꦮ) is an open source programming language, an interpreter to be precise, where you can write python code using javanese character. sawa iku

Rony Lantip 307 Jan 07, 2023
Sublime Text 2/3 style auto completion for ST4

Hippie Autocompletion Sublime Text 2/3 style auto completion for ST4: cycle through words, do not show popup. Simply hit Tab to insert completion, hit

Alexander Schepanovski 20 May 19, 2022
This is a Docker-based pipeline for preparing sextractor-ready multiwavelength images

Pipeline for creating NB422-detected (ODI) catalog The repository contains a Docker-based pipeline for preprocessing observational data. The pipeline

1 Sep 01, 2022
Defichain maxi - Scripts to optimize performance on defichain rewards

defichain_maxi This script is made to optimize your defichain vault rewards by m

kuegi 75 Dec 31, 2022
Automated moth pictures for biodiversity research

Automated moth pictures for biodiversity research

Ludwig Kürzinger 1 Dec 16, 2021
Python package for reference counting native pointers

refcount master: testing: This package is primarily for managing resources in native libraries, written for instance in C++, from Python. While it boi

CSIRO Hydroinformatics 2 Nov 03, 2022
Object-oriented programming (OOP) is a method of structuring a program by bundling related properties and behaviors into individual objects. In this tutorial, you’ll learn the basics of object-oriented programming in Python.

06_Python_Object_Class Introduction 👋 Objected oriented programming as a discipline has gained a universal following among developers. Python, an in-

Milaan Parmar / Милан пармар / _米兰 帕尔马 239 Dec 20, 2022
VCM EE1.2 P-layer feature map anchor generation 137th MPEG-VCM

VCM EE1.2 P-layer feature map anchor generation 137th MPEG-VCM

IPSL 6 Oct 18, 2022
A code base for python programs the goal is to integrate all the useful and essential functions

Base Dev EN This GitHub will be available in French and English FR Ce GitHub sera disponible en français et en anglais Author License Screen EN 🇬🇧 D

Pikatsuto 1 Mar 07, 2022
Proyectos de ejercicios básicos y avanzados hecho en python

Proyectos Básicos y Avanzados hecho en python Instalación: Tener instalado python 3.x o superior. Tener pip instalado. Tener virtualenv o venv instala

Karlo Xavier Chok 1 Dec 27, 2021
Turn your IPad into a Screen-Slaver with 1 simple Pythonista script

ScreenSlaver Turn your IPad into a Screen-Slaver with 1 simple Pythonista script

6 Jul 09, 2022
To check my COVID-19 vaccine appointment, I wrote an infinite loop that sends me a Whatsapp message hourly using Twilio and Selenium. It works on my Raspberry Pi computer.

COVID-19_vaccine_appointment To check my COVID-19 vaccine appointment, I wrote an infinite loop that sends me a Whatsapp message hourly using Twilio a

Ayyuce Demirbas 24 Dec 17, 2022
Usando Multi Player Perceptron e Regressão Logistica para classificação de SPAM

Relatório dos procedimentos executados e resultados obtidos. Objetivos Treinar um modelo para classificação de SPAM usando o dataset train_data. Class

André Mediote 1 Feb 02, 2022
Fast STL (ASCII & Binary) importer for Blender

blender-fast-stl-importer Fast STL (ASCII & Binary) importer for Blender based on https://en.wikipedia.org/wiki/STL_(file_format) Technical notes: flo

Iyad Ahmed 7 Apr 17, 2022
Experimental Brawl Stars v36.218 server emulator written in Python.

Brawl Stars v36 Experimental Brawl Stars v36.218 server emulator written in Python. Requirements: Python 3.7 or higher colorama Running the server In

8 Oct 31, 2021
Python framework to build apps with the GASP metaphor

Gaspium Python framework to build apps with the GASP metaphor This project is part of the Pyrustic Open Ecosystem. Installation | Documentation | Late

5 Jan 01, 2023
Simple cash register system made with guizero

Eje-Casher なにこれ guizeroで作った簡易レジシステムです。実際にコミケで使う予定です。 これを誰かがそのまま使うかどうかというよりは、guiz

Akira Ouchi 4 Nov 07, 2022
A Lynx that manages a group that puts the federation first.

Lynx Super Federation Management Group Lynx was created to manage your groups on telegram and focuses on the Lynx Federation. I made this to root out

Unknown 2 Nov 01, 2022