Title: Apply Operations Over Items In A List
Slug: apply_operations_over_items_in_lists
Summary: Apply Operations Over Items In A List
Date: 2016-05-01 12:00
Category: Python
Tags: Basics
Authors: Chris Albon

Method 1: map()



In [1]:

    
# Create a list of casualties from battles
battleDeaths = [482, 93, 392, 920, 813, 199, 374, 237, 244]



In [2]:

    
# Create a function that updates all battle deaths by adding 100
def updated(x): return x + 100



In [3]:

    
# Create a list that applies updated() to all elements of battleDeaths
list(map(updated, battleDeaths))









    Out[3]:





[582, 193, 492, 1020, 913, 299, 474, 337, 344]

Method 2: for x in y



In [4]:

    
# Create a list of deaths
casualties = [482, 93, 392, 920, 813, 199, 374, 237, 244]



In [5]:

    
# Create a variable where we will put the updated casualty numbers
casualtiesUpdated = []



In [6]:

    
# Create a function that for each item in casualties, adds 10
for x in casualties:
    casualtiesUpdated.append(x + 100)



In [7]:

    
# View casualties variables
casualtiesUpdated









    Out[7]:





[582, 193, 492, 1020, 913, 299, 474, 337, 344]

Method 3: lambda functions



In [8]:

    
# Map the lambda function x() over casualties
list(map((lambda x: x + 100), casualties))









    Out[8]:





[582, 193, 492, 1020, 913, 299, 474, 337, 344]