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diff --git a/tutorials/module_1/functions.ipynb b/tutorials/module_1/functions.ipynb new file mode 100644 index 0000000..6662537 --- /dev/null +++ b/tutorials/module_1/functions.ipynb @@ -0,0 +1,216 @@ +{ + "cells": [ + { + "cell_type": "markdown", + "id": "8e2f3fed-9592-4c3a-a0a3-1d9c8d58244f", + "metadata": {}, + "source": [ + "# Functions\n", + "\n", + "Like a traditional mathematical functions, python functions can take an\n", + "input, process it, and give an output. In python, the input variables\n", + "are referred to as *arguments*. Functions are blocks of code that is run\n", + "every time it’s called. This allows us to re-use code.\n", + "\n", + "Functions are defined by using the <code> def </code> keyword. Reminder:\n", + "it is important to keep track of indentations as it signifies the end of\n", + "the function when the indentation returns back to the same level.\n", + "\n", + "## Defining Functions\n", + "\n", + "### Simple function\n", + "\n", + "A simple function with no input variable can be useful if you need to\n", + "re-use code multiple times without having to re-write it." + ] + }, + { + "cell_type": "code", + "execution_count": 1, + "id": "b673514c-db14-4da7-8f6a-65402b27c3c6", + "metadata": {}, + "outputs": [], + "source": [ + "def function_name():\n", + " print(\"This is from a function\")" + ] + }, + { + "cell_type": "markdown", + "id": "b7cca02d-2d53-4acd-ada5-cb8221008b52", + "metadata": {}, + "source": [ + "### Defining a function with one input\n", + "We can pass variables through to the function to be processed as\n", + "follows:" + ] + }, + { + "cell_type": "code", + "execution_count": 2, + "id": "89f84f81-461a-42e3-9e7a-a6be2ac8c4d7", + "metadata": {}, + "outputs": [], + "source": [ + "def function(x):\n", + " print(x + \" is best\")" + ] + }, + { + "cell_type": "markdown", + "id": "0d0d30cb-83d1-438f-85b0-c5e3e49eff29", + "metadata": {}, + "source": [ + "Note input variables can be of any data type (integer, float, string,\n", + "etc.). \n", + "\n", + "### Returning values from a function If we want to calculate a\n", + "value and pass it back to the script for further use, we can use the\n", + "`return` keyword. Let’s define a linear function that takes two inputs,\n", + "`x` and `b`, computes the corresponding `y` value, and returns it so it\n", + "can be used elsewhere in the code." + ] + }, + { + "cell_type": "code", + "execution_count": 3, + "id": "5f2ff033-050c-4939-bab4-f55ec0de688b", + "metadata": {}, + "outputs": [], + "source": [ + "def function(x, b):\n", + " y = 3*x+b\n", + " return y" + ] + }, + { + "cell_type": "markdown", + "id": "a2ad94cf-6e16-4186-874c-972d6932858a", + "metadata": {}, + "source": [ + "For multiple output variables we can add \n", + "\n", + "## Calling functions Now that\n", + "we’ve covered defining functions we want to call the function in order\n", + "to execute the block inside the function. To do this, we simply re-call\n", + "the function name as follows." + ] + }, + { + "cell_type": "code", + "execution_count": 4, + "id": "4bff7ef2-630f-43d3-b54a-cc8214aa7034", + "metadata": {}, + "outputs": [ + { + "data": { + "text/plain": [ + "5" + ] + }, + "execution_count": 4, + "metadata": {}, + "output_type": "execute_result" + } + ], + "source": [ + "function(2,-1)" + ] + }, + { + "cell_type": "markdown", + "id": "caeeca6c-3442-4785-9d54-e39801ee3cf6", + "metadata": {}, + "source": [ + "Note that when running this code, nothing happens. This is because we\n", + "haven’t told the computer what to do with the output. Hence, if we wish\n", + "to store the output then we need to use the assign operator `=`." + ] + }, + { + "cell_type": "code", + "execution_count": 5, + "id": "b47437eb-050d-481e-a72b-201a7703b193", + "metadata": {}, + "outputs": [ + { + "name": "stdout", + "output_type": "stream", + "text": [ + "5\n" + ] + } + ], + "source": [ + "output = function(2,-1)\n", + "\n", + "print(output)" + ] + }, + { + "cell_type": "markdown", + "id": "8cd86a50-5dc6-42df-b651-a147b445cb57", + "metadata": {}, + "source": [ + "In case you want to return multiple output variable from a single\n", + "function we will have…\n", + "\n", + "## Summary" + ] + }, + { + "cell_type": "code", + "execution_count": 6, + "id": "d22da5ff-85ee-4658-a959-1a2b5df6eb9a", + "metadata": {}, + "outputs": [], + "source": [ + "def function_name(argument1, argument2, argument3):\n", + " output1 = argument1 * argument2 - argument3\n", + " output2 = argument2 + argument3\n", + " return output1, output2\n", + "\n", + "[solution1, solution2] = function_name(1,2,3)" + ] + }, + { + "cell_type": "markdown", + "id": "bd984f25-729f-437c-8df4-0feb75aa7ed8", + "metadata": {}, + "source": [ + "- `def` - defines a function. All the code that is indented underneath\n", + " is considered inside the function block.\n", + "- `function_name` - this is used to call the function block.\n", + "- `argument1` (optional) - input variable. This is data that can be\n", + " pass to the function. It is possible to have multiple variables\n", + " separated by a comma. As well as can be omitted if the function\n", + " should just give you an output such as.\n", + "- `return` (optional) - if you wish to return something to your\n", + " script, the return keyword is used. The keyword can be followed by\n", + " an output variable or a constant. For multiple output variables,\n", + " separate them by a comma." + ] + } + ], + "metadata": { + "kernelspec": { + "display_name": "Python 3 (ipykernel)", + "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": "3.13.2" + } + }, + "nbformat": 4, + "nbformat_minor": 5 +} |