Profile Every Column
Types, ranges, and unique counts at a glance.
Profile Every Column is a free Data Science Academy lesson on CoddyKit — lesson 2 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Data Science Academy learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.
Meet Every Column First
Before any fancy analysis, get to know each field. Profiling means learning each column's type, range, and quirks one by one. 🔍
Start With info
One call gives you column names, counts, and dtypes at a glance. Run info the moment a DataFrame loads to see its skeleton.
df.info()Check the dtypes
Numbers stored as text break your math silently. Reading the dtype of each column tells you what needs converting before analysis.
df.dtypesNumbers Versus Categories
Treat columns by their kind. Numeric fields get means and ranges, while categorical fields get counts of each label.
describe for Numbers
For numeric columns, one call summarizes count, mean, min, and quartiles. Use describe to spot impossible values fast.
df.describe()Count Unique Values
How many distinct entries does a column hold? nunique separates an ID column from a small category in one number.
df.nunique()value_counts for Categories
To profile a label column, tally each value. value_counts shows the most common categories and surprise typos at once.
df["plan"].value_counts()Find Missing Values Early
Gaps in a column change what is trustworthy. Counting nulls per column shows where data is thin before you rely on it.
df.isna().sum()Sanity-Check the Ranges
Ask if each min and max makes sense. A negative age or a future date is a red flag you want to catch during profiling.
Peek at Real Rows
Summaries hide texture, so look at actual examples too. A quick sample of rows reveals formatting issues numbers alone miss.
df.sample(5)Build a Column Inventory
Jot a one-line note per column: its meaning, type, and any issue. This inventory becomes your map for every later step.
Quick Check
You want the frequency of each category in a label column.
Recap: Know Each Column
You now profile with info, describe, nunique, and value_counts, then check nulls and ranges. This inventory grounds the analysis ahead. ✅
Frequently asked questions
Is the “Profile Every Column” lesson free?
Yes — the full text of “Profile Every Column” is free to read here on the web, and the Data Science Academy course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Data Science Academy course, upgrade to CoddyKit PRO.
What will I learn in “Profile Every Column”?
Types, ranges, and unique counts at a glance. You practise Data Science Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start Data Science Academy?
No prior experience is required. Data Science Academy on CoddyKit is structured for beginners through advanced learners; this is — lesson 2 of 4, so you can start here or from the beginning and move at your own pace.
How long does the “Profile Every Column” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this Data Science Academy lesson?
Yes. Every Data Science Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- Frame the Questions First
- Profile Every Column
- Univariate Then Bivariate
- Write Down What You Found