Skip to content
Codeloom

Topics / Pandas & NumPy

Pandas & NumPy

Data manipulation in Python with Pandas and NumPy.

Why learn Pandas & NumPy?

  • The default toolkit for tabular data in Python.

  • Used by analysts, scientists, and ML engineers daily.

  • Replaces spreadsheets for any non-trivial dataset.

  • Foundation for everything from EDA to ML feature engineering.

What you can build with Pandas & NumPy

Cleaning and exploring datasets ETL and data pipelines Feature engineering for ML Reporting and ad-hoc analysis

Pandas & NumPy tutorials

19 articles · page 1 of 1

Hand-written tutorials, ordered as a recommended learning path.

  1. 01 What Is Pandas? A clear introduction to pandas — what DataFrames and Series are, why analysts and ML engineers live in it, how to install it, and a tiny first end-to-end example.
  2. 02 DataFrames Basics A practical guide to the daily DataFrame moves — read_csv and read_json, head and info, column selection, loc vs iloc, boolean filtering, sorting, and value_counts.
  3. 03 groupby & merge A practical guide to combining and summarising DataFrames — groupby with named aggregations, multi-column aggregates, the four merge styles, and stacking with concat.
  4. 04 Pandas Cheat Sheet A practical Pandas cheat sheet covering 50 essential DataFrame operations including selection, filtering, grouping, merging, and data cleaning with copy-paste examples.
  5. 05 Pandas Plotting Create effective charts directly from Pandas DataFrames with plot(), including line, bar, histogram, scatter, box plots, and customization tips.
  6. 06 read_csv Options Master pandas read_csv with practical examples for every important parameter including dtypes, parsing dates, handling missing data, chunked reading, and encoding.
  7. 07 apply vs Vectorize When to reach for .apply and when vectorized operations win. A practical comparison with benchmarks, mental models, and the patterns that keep Pandas code both readable and fast.
  8. 08 Categorical Data Use Pandas Categorical dtype to cut memory, speed up groupby, and encode ordered categories cleanly with practical conversion and pitfall notes.
  9. 09 Data Cleaning Hands-on pandas patterns for cleaning messy real-world data, covering missing values, types, duplicates, strings, and a reliable cleaning pipeline.
  10. 10 GroupBy Master pandas groupby with single and multi-column aggregations, named outputs, transform, and filter for clean analytical pipelines.
  11. 11 Merge/Join Pick the right pandas combining function with clear examples of inner, outer, left, right joins, concat, and the gotchas that cause silent bugs.
  12. 12 Performance Practical pandas speedups: vectorization, dtype tuning, categorical columns, eval/query, and chunked I/O patterns that turn slow scripts into responsive pipelines.
  13. 13 MultiIndex A practical guide to Pandas MultiIndex: when to use it, how it really works, and the slicing, stacking, and groupby patterns that make hierarchical data manageable.
  14. 14 Pivot Tables Learn how to use pandas pivot_table to summarize, reshape, and aggregate data with multiple indexes, columns, and custom aggregation functions in real workflows.
  15. 15 String Methods A practical tour of the Pandas .str accessor: cleaning text, extracting patterns, splitting and joining, dealing with missing values, and writing string code that stays fast.
  16. 16 Time Series Work with datetime indexes, resampling, rolling windows, lag features, and timezone gotchas to analyze time series cleanly in pandas.
  17. 17 Window Functions Use Pandas rolling, expanding, and ewm window functions to compute moving averages, running totals, and time-aware aggregations with clear examples.
  18. 18 Window Functions Master Pandas window functions: rolling averages, expanding cumulative stats, exponential weighting, groupby + rolling, and custom window operations.
  19. 19 Performance Tips Speed up Pandas code with vectorization, categorical dtypes, chunked reading, eval/query, PyArrow backend, and memory profiling techniques.