Imagine that we want to print numbers from 1 to 100.
Of course, we can do it manually:

But it’ll take too long! 

If we have to print numbers from 1 to 1000000, we will spend our whole lives counting manually!

To handle this problem, we will use the `for` loop with the `range()` function!

# Printing all numbers from 0 to 100
for i in range(101):
  print(i)

The ``range()`` function returns a sequence of numbers starting from 0 (by
default) if the initial limit is not specified, and it increments by 1 (by
default) until a final limit is reached (the final limit is not included). 

The form of the ``range()`` function: ``range(start, end, step)``.

If we want to work with decreasing numbers, we need to input a negative
*step* argument into the ``range()`` function.

# Increasing
# Printing numbers from 0 to 10
for i in range(0, 11, 1):
  print(i)

# Decreasing
# Printing numbers from 10 to 0
for i in range(10, -1, -1):
  print(i)

We start learning Python loops with the for loop. A for loop is used for iterating over a sequence. Let's go!

With the while loop, we can execute a set of statements as long as a condition is true. We are going to work with this loop and handle different problems!

A nested loop is a loop inside a loop. Sound difficult? Don't worry! We will handle this loop!