File Handling & Serialization
Modern programs rarely operate in isolation. They read text from configuration files, load datasets from disk, store logs, write results, exchange information with web APIs, or persist objects for later use. Python supports all of this through file handling and serialization, two fundamental techniques every data scientist and developer must master.
File handling is the foundation: opening files, reading their contents, writing results, and managing where data lives on your system.
Serialization builds on this capability by converting Python objects—lists, dictionaries, or even custom classes—into formats that can be stored and restored later. Sometimes this means using a human-readable format such as JSON, and sometimes a Python-specific binary representation like pickle.
In this chapter, we explore:
- reading and writing text files
- handling structured formats like CSV and JSON
- serializing Python objects with
pickle - managing file paths with
pathlibmodule - understanding when to choose each technique
By the end, you will know how to move data into and out of Python safely, efficiently, and in the right format for your needs.