Scripts and modules

Often one collects functions in a script. This creates a module with additional Python functionality. To demonstrate this, we create a module by collecting functions in a single file, for example smartfunctions.py:

def f(x):
    return 2*x + 1
def g(x):
    return x**2 + 4*x - 5
def h(x):
    return 1/f(x)

Again, the command exec(open('smartfunctions.py').read()) makes these functions available to your IPython shell (note that there is also the IPython magic function run). In Python terminology, one says that they are put into the actual namespace.

Alternatively, the modules  can be imported by the command import. It creates a named namespace. The command from puts the functions into the general namespace:

import smartfunctions
print(smartfunctions.f(2))      # 5

from smartfunctions import g    #import just this function
print(g(1)) # 0
  
from smartfunctions import *    #import all
print(h(2)*f(2))                # 1.0