# modules.py
'''
Use Python modules and write your own by splitting your code into
different files.
'''

# Create a file with your functions, e.g. functions.py.
# functions.py
'''
Module containing some functions.
'''

x = 5

def fib(n):
    a, b = 0, 1
    while b < n:
        print(b)
        a, b = b, a+b

def fib2(n):
    result = []
    a, b = 0, 1
    while b < n:
        result.append(b)
        a, b = b, a+b
    return result


# Import the module.
import functions

# Use the functions defined in your module.
functions.fib(3)

# Import selectively.
from functions import fib, fib2
a = fib(3)

# Import all.
from functions import *
a = fib(3)
b = fib2(3)

# Import a module with a specified name.
import functions as fun
a = fun.fib(3)
b = fun.fib2(3)

import numpy as np
np.sin(np.pi/2)

# Acces the doc string.
fun.__doc__
np.__doc__


# Reload a module when it is changed (Python 3)
import importlib
importlib.reload(fun)
importlib.reload(np)

# Search path for module: local directory and PYTHONPATH.
import sys
sys.path