pandas
Tabular data loading, cleaning and aggregation.
pandas is taught here in 12 lessons, running from Series and DataFrame through to Debugging pandas: SettingWithCopy, dtype and index surprises. Each lesson takes one topic, shows the working code, and links onward to the next, so the course can be read straight through in order.
| Track | Python & Data Science |
| Lessons | 12 |
| Level | Beginner to intermediate |
| Reading time | about 3 hours |
| Prerequisites | Helpful, but not required: NumPy |
Lessons
- Series and DataFrameThe two data structures, what the index really is, and how to inspect a new dataset before touching it.
- Reading and writing dataCSV, Excel, JSON and SQL in and out — plus the encoding, dtype and date problems that appear on real files.
- Selecting, filtering and cleaningloc, iloc, boolean filters, missing values and type conversion — the routine work that makes up most of a data task.
- Grouping, joining and reshapingsplit-apply-combine with groupby, merging tables like SQL, and moving between long and wide layouts.
- The index in depth: MultiIndex, set_index and reindexHierarchical indexes, stack and unstack, reindex, and the alignment rules that quietly decide whether your numbers land on the right rows.
- Dates, times and time seriesto_datetime, DatetimeIndex, resample, rolling, shift, asfreq, time zones and business calendars - working with data that moves through time.
- Pivot tables and crosstabpivot_table with aggregators, crosstab with normalisation, margins, multi-level columns and flattening the result into something tableable.
- String operations with .strThe .str accessor, regex extraction, contains and replace, splitting columns apart, and cleaning text columns without a Python loop.
- apply, map and writing fast pandas codemap versus apply versus vectorised operations, transform for group-aligned results, pipe for readable chains, and why a row-wise loop is a last resort.
- Categoricals, dtypes and memory optimisationThe category dtype, nullable integers and booleans, deliberate downcasting, and how to measure what a frame actually costs in memory.
- Plotting and quick exploratory chartsdf.plot, the chart kinds worth knowing, subplots for comparisons, styling, and when to hand the figure over to Matplotlib or Seaborn.
- Debugging pandas: SettingWithCopy, dtype and index surprisesThe three failures that waste the most time - chained assignment, silent dtype coercion and misaligned indexes - and how to catch them early.
More in Python & Data Science
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FAQ
How long does the pandas course take?
It has 12 lessons, about 3 hours of reading. Expect roughly twice that if you type out and run every example.
Do I need prior experience for pandas?
Not strictly. It helps to have read NumPy first, because some lessons build on it, but every lesson explains its own assumptions.
What should I read after pandas?
Continue with Matplotlib (12 lessons), the next course in Python & Data Science.