What is Function Definition?
A reusable block of organised code designed to perform a single, related action. Defined using the def keyword, functions accept inputs, process them, and return outputs, promoting modularity and reducing code duplication across larger data analysis projects and complex scripting environments.
Function Definition,
explained properly.
Not a flashcard answer — the working meaning, where you'll meet it, and why professionals who use it precisely get taken more seriously.
A reusable block of organised code designed to perform a single, related action. Defined using the def keyword, functions accept inputs, process them, and return outputs, promoting modularity and reducing code duplication across larger data analysis projects and complex scripting environments.
Understanding Function Definition on paper is one thing — using it confidently at work is another. In professional settings, this is the kind of term that separates people who talk about Python For Data Analysis from people who are trusted to make decisions in it. Recruiters and managers listen for it in interviews, and colleagues notice immediately whether you use it precisely or vaguely.
At OnlineUni, Function Definition is taught in full working context inside Certificate in Python For Data Analysis — applied to real Python For Data Analysis scenarios, not memorised in isolation.
Indicative index of skill mentions in professional job postings (2019 = 1)
What mastering it
is worth.
Learning terms one definition at a time builds vocabulary. Completing the programme builds what employers pay for: certified capability.
Certified professionals are promoted faster, shortlisted more often and paid a documented premium over equally experienced but uncertified colleagues — and the premium compounds with seniority, so the earlier you certify, the longer it pays.
Fluency, not flashcards
Function Definition and every related concept taught in working context, so you can use them under pressure.
A verifiable credential
A shareable digital certificate in Python For Data Analysis for LinkedIn and your CV the day you pass.
Salary leverage
Certified Python For Data Analysis capability is exactly what the uplift figures here are paid for.
Momentum
Self-paced, online, from £79 — most learners finish their first certificate within two months.
Indicative ranges from published continuing-education salary studies, by career stage
Certificate in Python For Data Analysis
A self-paced online Certificate programme with 3 modules, an online assessment and a verifiable digital certificate you can share on LinkedIn the day you pass.
- 7,041 professionals enrolled
- 4.8★ learner rating
- Study from anywhere · no fixed timetable
- Fast-track option: finish in as few as 20 days
More terms from
this glossary.
Every term below is taught inside the same programme — read them all free, then study them properly.
Stop looking terms up. Start being the one who explains them.
Certificate in Python For Data Analysis covers Function Definition and everything around it — from £79, entirely online.