{"id":2629,"date":"2020-09-04T10:55:39","date_gmt":"2020-09-04T10:55:39","guid":{"rendered":"https:\/\/idiagress.com\/vinaaypatil\/?p=2629"},"modified":"2023-10-28T12:25:15","modified_gmt":"2023-10-28T12:25:15","slug":"1-6-loops-and-iterations","status":"publish","type":"post","link":"https:\/\/idiagress.com\/vinaaypatil\/2020\/09\/04\/1-6-loops-and-iterations\/","title":{"rendered":"1.6 Loops and Iterations"},"content":{"rendered":"\n

Understanding Loops and Iterations in Python<\/h2>\n\n\n\n

Loops are a fundamental concept in programming that allows us to execute a set of instructions repeatedly until a specific condition is met. They are essential for automating repetitive tasks and solving complex problems more efficiently. In Python, loops are a crucial part of the language, and there are several ways to implement them.<\/p>\n\n\n\n

The Need for Iterations<\/h3>\n\n\n\n

In mathematics and computer science, we often encounter problems that require a repetitive approach to reach a solution. This approach is known as “iteration.” It involves repeatedly applying a set of steps until a desired result is achieved. Let’s explore this concept further with an example.<\/p>\n\n\n\n

The Guessing Game: Finding the Square Root<\/h3>\n\n\n\n

Suppose we want to calculate the square root of a number, such as 196. We can represent this problem as an equation:Copy code<\/p>\n\n\n\n

x^2 = 196<\/code><\/p>\n\n\n\n

Our objective is to find the value of ‘x.’ To keep things simple, we’ll focus on finding the positive square root.<\/p>\n\n\n\n

Two things are evident about the solution:<\/p>\n\n\n\n

    \n
  1. The square root is greater than 0.<\/li>\n\n\n\n
  2. The square root is less than 196.<\/li>\n<\/ol>\n\n\n\n

    This information defines the range of our solution, which is from 0 to 196. To find the square root, we could start at 0 and increment our guess step by step until we arrive at the correct value.<\/p>\n\n\n\n

    A python loop for the solution will appear in the following manner:<\/p>\n\n\n\n

     <\/td><\/tr>
    for<\/span> _x <\/span>in<\/span> range<\/span>(<\/span>0<\/span>,<\/span>196<\/span>,<\/span>1<\/span>):
    \u00a0 \u00a0 <\/span><\/span>if<\/span> (_x * _x) == <\/span>196<\/span>:
    \u00a0 \u00a0 \u00a0 \u00a0 <\/span><\/span>print<\/span>(<\/span>\"Square root of 196 is: \"<\/span>, _x) <\/span><\/kbd><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
    <\/div>\n\n\n\n

    Now, let’s implement the square root guessing program in Python, which prompts the user to input a number and utilizes a loop to find the square root.\u00a0 <\/span>(sqaure_root.py<\/strong>)<\/p>\n\n\n\n

    square_root.py<\/b><\/span><\/td><\/tr>
    # program to 'Guess' square root of a number
    # Ask for number for calculating square root
    <\/span>_s = <\/span>int<\/span>(<\/span>input<\/span>(<\/span>\"Enter number for calculating square root<\/span><\/kbd>: \"<\/span>))
      <\/span>
    <\/span># loop for guessing, range 0 to _s, with step increase of 1
    <\/span>for<\/span> _x <\/span>in<\/span> range<\/span>(_s):
        <\/span><\/span>if<\/span> (_x*_x) == _s:
            <\/span><\/span>print<\/span>(<\/span>\"Square root of \"<\/span>, _s, <\/span>\" is: \"<\/span>, _x)
        <\/span><\/span>else<\/span>:
            <\/span><\/span>print<\/span>(_s, <\/span>\" is not a perfect square\"<\/span>)<\/span><\/kbd>
    <\/span><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

    One key observation: the    <\/span>\u2018range\u2019<\/b>    <\/span>in the     <\/span>\u2018for\u2019<\/b>    <\/span>loop command is shortened <\/span><\/i><\/b><\/p>\n\n\n\n

    <\/div>\n\n\n\n

    for<\/span> _x <\/span>in<\/span> range<\/span>(_s): instead of <\/span>for<\/span> _x <\/span>in<\/span> range<\/span>(0, _s, 1):<\/span><\/p>\n\n\n\n

    <\/div>\n\n\n\n

    Simplifying the Range<\/h3>\n\n\n\n

    You may have noticed that we use for _x in range(_s)<\/code> instead of the more detailed for _x in range(0, _s, 1)<\/code>.<\/p>\n\n\n\n

    In Python, when you don’t specify the starting point and step size, the default values are assumed to be 0 and 1, respectively. So, we can simply use range(_s)<\/code> to achieve the same result.<\/p>\n\n\n\n

    The output for our program is as follows:<\/p>\n\n\n\n

    <\/div>\n\n\n
    \n
    \"\"<\/figure>\n<\/div>\n\n\n
    <\/div>\n\n\n\n

    The output is quite\u00a0absurd<\/i><\/b>. <\/p>\n\n\n\n

    Analyzing the Output<\/h3>\n\n\n\n

    Upon analyzing the output, we observe the following issues:<\/p>\n\n\n\n