In this tutorial, we are going to print Fibonacci numbers until a given number by using a while loop in Python.

This program generates all the Fibonacci numbers up to a given number

using a while loop.`n`

## Simple Code:

```
n = int(input("Enter a number: "))
a = 0
b = 1
while a <= n:
print(a)
a = b
b = a + b
```

## Output:

```
Enter a number: 57
0
1
2
4
8
16
32
```

## Code with Comments:

```
# Here we take Input from user
n = int(input("Enter a number: "))
# Initialize variables
a = 0
b = 1
# Loop until a is less than or equal to n
while a <= n:
# Print the current Fibonacci number
print(a)
# Update a and b to generate the next Fibonacci number
a = b
b = a + b
```

## Explanation:

We start by getting the input from the user by using `input` function, which is the upper limit

. `n`

Then, we initialize two variables

and `a`

to 0 and 1, respectively. `b`

These variables will keep track of the current and next Fibonacci numbers in the sequence.

We use a while loop to repeatedly check whether

is less than or equal to `a`

. `n`

If it is, we print the current Fibonacci number using the variable

, and then update the variables `a`

and `a`

to generate the next Fibonacci number in the sequence.`b`

The update is done using the expression `a = b` and `b = a + b` which first sets

to `a``b`

(i.e., the next Fibonacci number) and then sets

to `b`

(i.e., the sum of the current and next Fibonacci numbers).`a + b`

This process continues until the current Fibonacci number

is greater than `a`

, at which point the`n`