Question

What will the following code display? for number in range(0, 501, 100): print(number)

Short answer

Answer: The sequence of numbers generated and displayed by the code snippet is 0, 100, 200, 300, 400, 500.

Step-by-step solution

Understand the code and the range() function

The given code is a for loop with a range() function. The range() function in Python creates a sequence of numbers starting from the first parameter (0), being incremented by the second parameter (100) and stops just before reaching the third parameter (501).

Write the sequence of numbers generated by the range() function

Now that we understand the range() function parameters, let's generate the sequence of numbers. The sequence starts at 0, incremented by 100, and stops before reaching 501. The sequence of numbers will be: [0, 100, 200, 300, 400, 500].

Iterate through the sequence using the for loop

The for loop goes through the generated sequence, assigns each number to the variable 'number', and then prints it out. The loop will print out all the numbers in the sequence as it iterates through all the elements of the sequence.

Determine the code's final output

The code will display the following numbers separated by a newline, as it iterates through the range: 0 100 200 300 400 500

Key concepts

range() function

In Python, the range() function is a versatile utility for generating sequences of numbers, which is particularly useful in loops. This function can take one, two, or three arguments. For instance, range(5) produces numbers from 0 to 4, great for zero-based indexing in Python. With two arguments, range(1, 5) starts the sequence at the first number and ends just before the second number, yielding 1, 2, 3, and 4.

The real magic happens with three arguments, where range(0, 501, 100) starts at 0, ends just before 501, and steps by 100, giving us the sequence 0, 100, 200, 300, 400. Think of the third argument as the 'stride' in our step—how broad each leap in our number sequence is. This control over the sequence density allows for precision in iteration, looping exactly as needed for the task at hand.

sequence iteration

Sequence iteration in Python is the process of traversing through objects like lists, tuples, or ranges one by one. A powerful feature of Python is its ability to loop through these sequences using simple and readable code. When a for loop is initiated, Python iterates over each element in the sequence, doing something with each element, such as printing it, until the sequence ends. For example, for number in [0, 1, 2, 3]: print(number) would print each number in the list.

The convenience of sequence iteration lies in automation: once you set up the loop, Python handles each element in order, making it a go-to for repetitive tasks. Imagine having to individually print each holiday card address from a list of hundreds—sequence iteration does that monotonous work for you, with unfailing accuracy.

Python loops

Loops in Python are fundamental constructs that enable the execution of a block of code repeatedly. The for loop is particularly useful for iterating over a sequence, executing a block of code for each element. This loop works in tandem with the range() function to perform controlled iterations.

In our exercise example, the for loop uses range(0, 501, 100) to iterate from 0 to 400 in steps of 100. With inventive use of loops, a mountainous task like performing calculations on thousands of data points is reduced to a few lines of code. Loops form the beating heart of automation in Python—write once, run ad infinitum, making them an indispensable tool in a programmer’s toolkit.