range.py

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# Tutorial: Range() built-in function in Python
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# Code here explaining concept with comments to guide


# Range func is inbuilt function having arguments passed to it below:
# if we use just a single argument range(n) - it takes 0 by default as starting point and follows for n values i.e. ending at n-1
# range(n) = range(0,n) as exclusive of its upper limit.
# range(start,stop,step) {start is inclusive and stop is exclusive and step is the value of increament or decreament in each iteration of numbers
# { By default, if we do not state the third argument it is taken as +1 }

# Syntax:

n = 5

x = range(0, n, 1)  # goes from 0 to n-1 with step size of 1 equal to range(n)

y = range(n, 0, -2)  # goes from n to 1 with step size of -2

# Here I will set up an example for you all to clarify any more doubts about range()

# Example:

t = range(1, 11)
for number in t:
    if number % 2 == 0:
        print(number)


# The above example gets us all the even numbers within the range [1,10].

# So range deals with both increament as well as decreament hence very useful while calling for loops.
# Also range() returns a sequence of numbers included in | range(start,stop,step) |

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# Challenge: Take user based input n and then compute the sum of first n natural numbers(1,2,3,4....,n) and print the sum. Use the range function only and not the direct formula.
# Example: Input - 5
#          Output - 15
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