Write a for loop that displays all of the odd numbers, 1 through 49.

Understanding how to iterate over a specific set of numbers, like odd numbers, is a fundamental skill in programming. In Python, when tasked with displaying all odd numbers within a certain range, one efficient way to do so is by using a for loop. The loop executes a block of code repeatedly, based on the conditions set.

Let's say we need to list the odd numbers from 1 to 49. We can leverage the for loop, which iterates over a sequence of numbers produced by the range function. Within this loop, we specifically target odd numbers by checking if the current number has a remainder when divided by 2. This is a common approach to filtering out even numbers, allowing the loop to 'skip' them and only execute the print statement for the odd numbers. To emphasize the simplicity, we can think of the loop as a filtering mechanism, where only numbers that pass the 'odd' test are displayed.

The modulo operator, represented by the symbol %, is a tool that returns the remainder of a division between two numbers. In Python, it's quite common to use the modulo operator when we need to determine whether a number is even or odd. If we take any integer and divide it by 2, the remainder will be 0 if it's even, and 1 if it's odd.

For example, in our task to print odd numbers from 1 through 49, we use i % 2 == 1 as a condition. Here's what happens: for each number i in our range, we calculate i divided by 2 and look at the remainder; if it's 1 (i is odd), we execute the print() function. This simple yet powerful operation allows us to effortlessly sift through numbers and pick out those with the desired property—in this case, being odd.

The range function in Python is an invaluable tool when we need to generate a series of numbers within a specific interval. When using it in a for loop, it determines which numbers to loop over. The signature of this function is range(start, stop[, step]).

In our odd numbers example, range(1, 50) generates a sequence from 1 to 49, as it stops right before the stop parameter. The start parameter defines where the sequence begins, and the optional step parameter indicates the increment between numbers in the sequence, which defaults to 1 when omitted.

Importantly, when inputting the values for start and stop, it's crucial to remember that stop is exclusive. If we want to include the number 49 in our iteration, we set the stop value to 50.