Python functions as dictionary values

Dec 21, 2015 • 2 minutes to read • Last Updated: Oct 29, 2017

Pro pythonistas will tell you that you should actually be using python with higher order functions & as first class functions. Passing around functions are any programming languages greatest attribute. Here’s a trick to making function calls using python dictionaries.

Consider you have some functions add, subtract, divide and multiply. You could call these functions from a python dictionary like so:

def add(x, y):
    return x+y

def subtract(x, y):
    return x-y

def divide(x, y):
    return x/y

def multiply(x, y):
    return x*y

x, y = 20, 10
operations = {
    'add': add,
    'subtract': subtract,
    'divide': divide,
    'multiply': multiply,
}

# add variables x & y
print operations['add'](x, y)
# 30

# subtract variables x & y
print operations['subtract'](x, y)
# 10

# divide variables x & y
print operations['divide'](x, y)
# 2

# multiply variables x & y
print operations['multiply'](x, y)
# 100

To use variable size of arguments you could call the operations dictionary with *args

def add(*args):
    total = 0
    for i in args:
        total += i
    return total

def subtract(x, y):
    return x-y

x, y, z = 20, 10, 5
p, q, r = 30, 40, 50

operations = {
    'add': add,
    'subtract': subtract
}

# add variables x, y, z, p, q, r
print operations['add'](x, y, z, p, q, r)
# 155


# subtract variables x & y
print operations['subtract'](x, y)
# 10

I would love to hear what you think about this post, also know about your tricks to using python in the comments below.

Python functions as dictionary values

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