{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "**Note**: Click on \"*Kernel*\" > \"*Restart Kernel and Run All*\" in [JupyterLab](https://jupyterlab.readthedocs.io/en/stable/) *after* finishing the exercises to ensure that your solution runs top to bottom *without* any errors. If you cannot run this file on your machine, you may want to open it [in the cloud ](https://mybinder.org/v2/gh/webartifex/intro-to-data-science/main?urlpath=lab/tree/00_python_in_a_nutshell/03_exercises_loops.ipynb)." ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "# Chapter 0: Python in a Nutshell (Coding Exercises)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "The exercises below assume that you have read the preceeding content sections.\n", "\n", "The `...`'s in the code cells indicate where you need to fill in code snippets. The number of `...`'s within a code cell give you a rough idea of how many lines of code are needed to solve the task. You should not need to create any additional code cells for your final solution. However, you may want to use temporary code cells to try out some ideas." ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Simple Loops" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "`for`-loops are extremely versatile in Python. That is different from many other programming languages.\n", "\n", "Let's create a `list` holding the numbers from `1` to `12` in an unordered fashion, like `numbers` below, loop over the numbers on a one-by-one basis, and implement simple **filter** logics." ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "numbers = [7, 11, 8, 5, 3, 12, 2, 6, 9, 10, 1, 4]" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "**Q1**: Fill in the *condition* in the `if` statement such that only numbers divisible by `3` are printed!" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "for number in numbers:\n", " if ...:\n", " print(...)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "An easy way to loop over a `list` in a sorted manner, is to wrap it with the built-in [sorted() ](https://docs.python.org/3/library/functions.html#sorted) function.\n", "\n", "**Q2**: Fill in the condition of the `if` statement such that only odd numbers are printed out!" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "for number in sorted(numbers):\n", " if ...:\n", " print(...)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "Whenever we want to loop over numbers representing a [series ](https://en.wikipedia.org/wiki/Series_%28mathematics%29) in the mathematical sense (i.e., a rule to calculate the next number from its predecessor), we may be able to use the [range() ](https://docs.python.org/3/library/functions.html#func-range) built-in.\n", "\n", "For example, to loop over the whole numbers from `0` to `9` (both including) in order, we could write them out in a `list` like in the following task.\n", "\n", "**Q3**: Fill in the call to the [print() ](https://docs.python.org/3/library/functions.html#print) function such that the squares of the `numbers` are printed out!" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "for number in [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]:\n", " print(...)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "**Q4**: Read the documentation on the [range() ](https://docs.python.org/3/library/functions.html#func-range) built-in! It may be used with either one, two, or three inputs. What do `start`, `stop`, and `step` mean? Fill in the calls to [range() ](https://docs.python.org/3/library/functions.html#func-range) and [print() ](https://docs.python.org/3/library/functions.html#print) to mimic the output of **Q3**!" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "for number in range(...):\n", " print(...)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "**Q5**: Fill in the calls to [range() ](https://docs.python.org/3/library/functions.html#func-range) and [print() ](https://docs.python.org/3/library/functions.html#print) to print out *all* numbers from `1` to `10` (both including)!" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "for number in range(...):\n", " print(...)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "**Q6**: Fill in the calls to [range() ](https://docs.python.org/3/library/functions.html#func-range) and [print() ](https://docs.python.org/3/library/functions.html#print) to print out the *even* numbers from `1` to `10` (both including)! Do *not* use an `if` statement to accomplish this!" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "for number in range(...):\n", " print(...)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "**Q7**: Fill in the calls to [range() ](https://docs.python.org/3/library/functions.html#func-range) and [print() ](https://docs.python.org/3/library/functions.html#print) to print out the *odd* numbers from `10` to `1` (both including) going backwards!" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "for number in range(...):\n", " print(...)" ] } ], "metadata": { "kernelspec": { "display_name": "intro-to-data-science", "language": "python", "name": "intro-to-data-science" }, "language_info": { "codemirror_mode": { "name": "ipython", "version": 3 }, "file_extension": ".py", "mimetype": "text/x-python", "name": "python", "nbconvert_exporter": "python", "pygments_lexer": "ipython3", "version": "3.12.4" }, "toc": { "base_numbering": 1, "nav_menu": {}, "number_sections": false, "sideBar": true, "skip_h1_title": true, "title_cell": "Table of Contents", "title_sidebar": "Contents", "toc_cell": false, "toc_position": {}, "toc_section_display": false, "toc_window_display": false } }, "nbformat": 4, "nbformat_minor": 4 }