25 practical automations

CSV & spreadsheets

Clean, reshape, and understand tabular data. Each guide includes full code, usage instructions, and ideas for making it your own.

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PythonBeginner

Add a cumulative numeric total

Append a running decimal total in the current record order.

CSV & spreadsheets

PythonBeginner

Add lookup columns to a CSV

Enrich every input row with columns from a uniquely keyed lookup CSV.

CSV & spreadsheets

PythonBeginner

Append CSV files with identical columns

Combine several CSV files under one shared header.

CSV & spreadsheets

PythonBeginner

Break a CSV into fixed-size batches

Divide records into numbered CSV batches, each with its own header.

CSV & spreadsheets

PythonBeginner

Compare two CSV snapshots by unique key

Describe added, removed, and changed keyed CSV records.

CSV & spreadsheets

PythonBeginner

Convert CSV dates to ISO form

Convert one consistently formatted date column to YYYY-MM-DD.

CSV & spreadsheets

PythonBeginner

Convert CSV rows into JSON objects

Export a CSV as a JSON array with one object per data row.

CSV & spreadsheets

PythonBeginner

Convert tab-separated data to CSV

Read tab-delimited records and write correctly quoted comma-delimited CSV.

CSV & spreadsheets

PythonBeginner

Convert wide CSV measurements to long rows

Convert selected measurement columns into measure/value records.

CSV & spreadsheets

PythonBeginner

Count a two-column CSV cross-tab

Turn two categorical columns into a table of occurrence counts.

CSV & spreadsheets

PythonBeginner

Count distinct CSV values

Create a frequency table for every exact value in one column.

CSV & spreadsheets

PythonBeginner

Fill empty CSV cells with a default

Fill genuinely empty cells in one column without changing existing values.

CSV & spreadsheets

PythonBeginner

Filter CSV rows by an exact value

Copy only rows whose chosen field exactly matches a value.

CSV & spreadsheets

PythonBeginner

Find rows missing required CSV values

List data-record numbers and required fields that are empty or whitespace-only.

CSV & spreadsheets

PythonBeginner

Keep selected CSV columns

Create a CSV containing only the chosen columns, in your chosen order.

CSV & spreadsheets

PythonBeginner

Mask selected CSV columns

Replace every value in selected columns with a fixed mask.

CSV & spreadsheets

PythonBeginner

Remove duplicate CSV records by key

Keep the first row for each distinct combination of key values.

CSV & spreadsheets

PythonBeginner

Remove explicit thousands separators

Convert locale-style numeric strings into plain decimal strings.

CSV & spreadsheets

PythonBeginner

Replace an exact CSV field value

Standardize one exact value in a selected CSV column.

CSV & spreadsheets

PythonBeginner

Sort a CSV by text or number

Write rows sorted by one selected column.

CSV & spreadsheets

PythonBeginner

Split a CSV into one file per category

Create one numbered CSV for each distinct field value plus an index.

CSV & spreadsheets

PythonBeginner

Sum a numeric CSV field by group

Produce one exact decimal total for each group.

CSV & spreadsheets

PythonBeginner

Take a reproducible random CSV sample

Select a repeatable random subset while preserving source order.

CSV & spreadsheets

PythonBeginner

Transpose a small CSV

Turn input columns into rows and input records into numbered columns.

CSV & spreadsheets

PythonBeginner

Trim whitespace from CSV values

Remove leading and trailing whitespace from selected cell values.

CSV & spreadsheets