Introduction to Data Science in Python Week 1

The Python Programming Language: Functions

add_numbers is a function that takes two numbers and adds them together.

In [1]:

def add_numbers(x, y):

    return x + y

​

add_numbers(1, 2)

​

Out[1]:

3

add_numbers updated to take an optional 3rd parameter. Using print allows printing of multiple expressions within a single cell.

In [2]:

def add_numbers(x,y,z=None):

    if (z==None):

        return x+y

    else:

        return x+y+z

​

print(add_numbers(1, 2))

print(add_numbers(1, 2, 3))

3
6

add_numbers updated to take an optional flag parameter.

In [3]:

def add_numbers(x, y, z=None, flag=False):

    if (flag):

        print('Flag is true!')

    if (z==None):

        return x + y

    else:

        return x + y + z

print(add_numbers(1, 2, flag=True))

Flag is true!
3

Assign function add_numbers to variable a.

In [4]:

def add_numbers(x,y):

    return x+y

​

a = add_numbers

a(1,2)

3