postMay 10, 2026

Python lists — the workhorse of data work

#python#lists#basics

python

rows = ["alice", "bob", "carol"]

print(rows[0])      # alice
print(len(rows))    # 3

rows.append("dave") # add at end
rows.remove("bob")  # remove by value

for name in rows:
    print(name)

A list is an ordered collection of values. You create one with square brackets and access elements by their index, starting at zero. Lists can hold any type — numbers, strings, even other lists.

In data engineering, lists are everywhere. You read a CSV and get a list of rows. You query a database and get a list of records. You collect file paths from a directory into a list. Knowing how to add, remove, and iterate items is non-negotiable.