{ "cells": [ { "cell_type": "code", "execution_count": 1, "metadata": {}, "outputs": [], "source": [ "# integers or floating-points\n", "# -2 , 2,0, 10000000 => integers\n", "# 1.14, 3.33333333 => floats" ] }, { "cell_type": "code", "execution_count": 2, "metadata": {}, "outputs": [ { "data": { "text/plain": [ "3" ] }, "execution_count": 2, "metadata": {}, "output_type": "execute_result" } ], "source": [ "2 + 1" ] }, { "cell_type": "code", "execution_count": 3, "metadata": {}, "outputs": [], "source": [ "# java int someTwo = 2\n", "#python someTwo = 2" ] }, { "cell_type": "code", "execution_count": 4, "metadata": {}, "outputs": [ { "data": { "text/plain": [ "1" ] }, "execution_count": 4, "metadata": {}, "output_type": "execute_result" } ], "source": [ "2 - 1" ] }, { "cell_type": "code", "execution_count": 5, "metadata": {}, "outputs": [ { "data": { "text/plain": [ "4" ] }, "execution_count": 5, "metadata": {}, "output_type": "execute_result" } ], "source": [ "2 * 2" ] }, { "cell_type": "code", "execution_count": 6, "metadata": {}, "outputs": [ { "data": { "text/plain": [ "1.5" ] }, "execution_count": 6, "metadata": {}, "output_type": "execute_result" } ], "source": [ "3 / 2" ] }, { "cell_type": "code", "execution_count": 7, "metadata": {}, "outputs": [ { "data": { "text/plain": [ "2.0" ] }, "execution_count": 7, "metadata": {}, "output_type": "execute_result" } ], "source": [ "4 / 2" ] }, { "cell_type": "code", "execution_count": 8, "metadata": {}, "outputs": [ { "data": { "text/plain": [ "1" ] }, "execution_count": 8, "metadata": {}, "output_type": "execute_result" } ], "source": [ "# Floor division\n", "3 // 2" ] }, { "cell_type": "code", "execution_count": 9, "metadata": {}, "outputs": [ { "data": { "text/plain": [ "3" ] }, "execution_count": 9, "metadata": {}, "output_type": "execute_result" } ], "source": [ "# Modulo\n", "7 % 4" ] }, { "cell_type": "code", "execution_count": 10, "metadata": {}, "outputs": [ { "data": { "text/plain": [ "8" ] }, "execution_count": 10, "metadata": {}, "output_type": "execute_result" } ], "source": [ "# Powers\n", "2 ** 3" ] }, { "cell_type": "code", "execution_count": 11, "metadata": {}, "outputs": [ { "data": { "text/plain": [ "2.0" ] }, "execution_count": 11, "metadata": {}, "output_type": "execute_result" } ], "source": [ "# roots\n", "4 ** 0.5" ] }, { "cell_type": "code", "execution_count": 12, "metadata": {}, "outputs": [ { "data": { "text/plain": [ "105" ] }, "execution_count": 12, "metadata": {}, "output_type": "execute_result" } ], "source": [ "2 + 10 * 10 + 3" ] }, { "cell_type": "code", "execution_count": 13, "metadata": {}, "outputs": [ { "data": { "text/plain": [ "156" ] }, "execution_count": 13, "metadata": {}, "output_type": "execute_result" } ], "source": [ "(2 + 10) * (10 + 3)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "# variable assignments" ] }, { "cell_type": "code", "execution_count": 15, "metadata": {}, "outputs": [], "source": [ "# object a is assinged the number 5\n", "a = 5" ] }, { "cell_type": "code", "execution_count": 16, "metadata": {}, "outputs": [ { "data": { "text/plain": [ "10" ] }, "execution_count": 16, "metadata": {}, "output_type": "execute_result" } ], "source": [ "a + a" ] }, { "cell_type": "code", "execution_count": 17, "metadata": {}, "outputs": [], "source": [ "# reassign\n", "a = 10" ] }, { "cell_type": "code", "execution_count": 18, "metadata": {}, "outputs": [ { "data": { "text/plain": [ "10" ] }, "execution_count": 18, "metadata": {}, "output_type": "execute_result" } ], "source": [ "a" ] }, { "cell_type": "code", "execution_count": 19, "metadata": {}, "outputs": [], "source": [ "# a redefine itself\n", "a = a + a" ] }, { "cell_type": "code", "execution_count": 20, "metadata": {}, "outputs": [ { "data": { "text/plain": [ "20" ] }, "execution_count": 20, "metadata": {}, "output_type": "execute_result" } ], "source": [ "a" ] }, { "cell_type": "code", "execution_count": 21, "metadata": {}, "outputs": [ { "ename": "SyntaxError", "evalue": "invalid syntax (, line 1)", "output_type": "error", "traceback": [ "\u001b[0;36m File \u001b[0;32m\"\"\u001b[0;36m, line \u001b[0;32m1\u001b[0m\n\u001b[0;31m 4a = 10\u001b[0m\n\u001b[0m ^\u001b[0m\n\u001b[0;31mSyntaxError\u001b[0m\u001b[0;31m:\u001b[0m invalid syntax\n" ] } ], "source": [ "4a = 10" ] }, { "cell_type": "code", "execution_count": 22, "metadata": {}, "outputs": [], "source": [ "# WRONG: a this = 10\n", "# WORNG: a&!|()#@ = 10" ] }, { "cell_type": "code", "execution_count": 23, "metadata": {}, "outputs": [], "source": [ "# convention to use LOWER CASE AND UNDERSCORE\n", "# java: thisIsAVariable\n", "# python: this_is_a_variable PEP8 Standard" ] }, { "cell_type": "code", "execution_count": 24, "metadata": {}, "outputs": [], "source": [ "# why to use variables\n", "my_income = 100\n", "tax_rate = 0.1\n", "\n", "my_taxes = my_income * tax_rate" ] }, { "cell_type": "code", "execution_count": 25, "metadata": {}, "outputs": [ { "data": { "text/plain": [ "10.0" ] }, "execution_count": 25, "metadata": {}, "output_type": "execute_result" } ], "source": [ "# show my taxes\n", "my_taxes" ] }, { "cell_type": "code", "execution_count": 26, "metadata": {}, "outputs": [ { "data": { "text/plain": [ "True" ] }, "execution_count": 26, "metadata": {}, "output_type": "execute_result" } ], "source": [ "# limitation of floating (decimal) point numbers\n", "0.1 + 0.1 == 0.2" ] }, { "cell_type": "code", "execution_count": 27, "metadata": {}, "outputs": [ { "data": { "text/plain": [ "False" ] }, "execution_count": 27, "metadata": {}, "output_type": "execute_result" } ], "source": [ "0.1 + 0.1 + 0.1 == 0.3" ] }, { "cell_type": "code", "execution_count": 28, "metadata": {}, "outputs": [ { "data": { "text/plain": [ "False" ] }, "execution_count": 28, "metadata": {}, "output_type": "execute_result" } ], "source": [ "(0.1 + 0.1) + 0.1 == 0.3" ] }, { "cell_type": "code", "execution_count": 30, "metadata": {}, "outputs": [ { "data": { "text/plain": [ "0.30000000000000004" ] }, "execution_count": 30, "metadata": {}, "output_type": "execute_result" } ], "source": [ "0.1 + 0.1 + 0.1" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "# Representation error https://docs.python.org/3/tutorial/floatingpoint.html#representation-error" ] } ], "metadata": { "kernelspec": { "display_name": "Python 3", "language": "python", "name": "python3" }, "language_info": { "codemirror_mode": { "name": "ipython", "version": 3 }, "file_extension": ".py", "mimetype": "text/x-python", "name": "python", "nbconvert_exporter": "python", "pygments_lexer": "ipython3", "version": "3.7.6" } }, "nbformat": 4, "nbformat_minor": 4 }