Python Tutorial

# Python Program for Fibonacci Series

## What is fibonacci series?

Fibonacci series is an integer sequence where every number after the first two is the sum of the two preceding ones.

0 1 1 2 3 5 8 13 21 34 ... etc

## Fibonacci Series Algorithm

Fibonacci n'th term is calculated as sum of n-1'th term and n-2'th term.

```F{n}=F{n-1}+F{n-2}
where F{0} = 0 and F{1} = 1
```

## Python Program for Fibonacci Series using recursion functions

```#!/usr/bin/python

def calculate_fibonacci_val(num):
if num > 1:
return calculate_fibonacci_val(num-2) + calculate_fibonacci_val(num-1)
else:
return num

def get_fibonacci_series(limit):
result = []
count = 0
while(count < limit):
result.append(calculate_fibonacci_val(count))
count += 1
return result

limit = 10
print(get_fibonacci_series(limit))

```
Output:
```\$ python fibonacci_series.py
[0, 1, 1, 2, 3, 5, 8, 13, 21, 34]
```

## Python Program for Fibonacci Series using while loop

```#!/usr/bin/python

def get_fibonacci_series(limit):
result = []
count = 1
temp1 = count -1
temp2 = count
result.append(temp1)
result.append(temp2)
while(count < (limit-1)):
next_val = temp1 + temp2
temp1 = temp2
temp2 = next_val;
result.append(next_val)
count += 1
return result

limit = 10
print(get_fibonacci_series(limit))
```
Output:
```\$ python fibonacci_series.py
[0, 1, 1, 2, 3, 5, 8, 13, 21, 34]
```

## Python Program for Fibonacci Series using for loop with range method

```#!/usr/bin/python

def get_fibonacci_series(limit):
result = []
count = 1
temp1 = count -1
temp2 = count
result.append(temp1)
result.append(temp2)
for count in range(count, limit-1):
next_val = temp1 + temp2
temp1 = temp2
temp2 = next_val;
result.append(next_val)
return result

limit = 10
print(get_fibonacci_series(limit))
```
Output:
```\$ python fibonacci_series.py
[0, 1, 1, 2, 3, 5, 8, 13, 21, 34]
```

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