A Professional’s Tutorial to Python For Loops
More control flow, Python terms and concepts
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Welcome to fifth, in a series of tutorials that teach beginner Python specifically for aspiring data scientists. For an overview of these tutorials, click here.
Introduction
A previous tutorial (about if statements and while loops) in this series explored the essence of decision-making with the if
statement and ventured into the realm of repetition (or iteration) with the while
loop statement. We compared how if and while loops let your code mimic human-like decision making processes on a shopping trip.
These constructs, you might also consider akin to the dials and switches on a machine, empower programmers to carve out dynamic pathways in their algorithms. However, as we push the boundaries of complexity especially for data science, another tutorial remains ahead: the for
loop.
Abstract
Python, a prominent language in data science, offers an elegant and flexible construct for iteration: the for
loop. This tutorial carefully explains its intricacies, the basic structure, and how it works with iterables such as results of the range()
function.
The tutorial further highlights the brevity and efficiency of list comprehensions, while emphasizing performance considerations. By mastering Python's for
loop, professionals can tackle and master many data processes and analytical tasks.
The Basic For Loop Structure
A loop, by its very essence, allows for repeated execution of a sequence of statements, instructions, code, or operations. The for
loop in Python is distinctively characterized by its ability to iterate over sequences, be it a list, a string, or DataFrame, the results of the range()
function, or another similar object.
A rudimentary example:
fruits = ["apple", "banana", "cherry"]
for fruit in fruits:
print(fruit)
Here, the loop runs three times. On each iteration the look will print each…