PyPI Changelog Tests License

Tool for viewing the difference between two CSV, TSV or JSON files. See Generating a commit log for San Francisco’s official list of trees (and the sf-tree-history repo commit log) for background information on this project.

pip install csv-diff

Consider two CSV files:

one.csv

id,name,age
1,Cleo,4
2,Pancakes,2

two.csv

id,name,age
1,Cleo,5
3,Bailey,1

csv-diff can show a human-readable summary of differences between the files:

$ csv-diff one.csv two.csv --key=id
1 row changed, 1 row added, 1 row removed
1 row changed
 Row 1
 age: "4" => "5"
1 row added
 id: 3
 name: Bailey
 age: 1
1 row removed
 id: 2
 name: Pancakes
 age: 2

The --key=id option means that the id column should be treated as the unique key, to identify which records have changed.

The tool will automatically detect if your files are comma- or tab-separated. You can over-ride this automatic detection and force the tool to use a specific format using --format=tsv or --format=csv.

You can also feed it JSON files, provided they are a JSON array of objects where each object has the same keys. Use --format=json if your input files are JSON.

Use --show-unchanged to include full details of the unchanged values for rows with at least one change in the diff output:

% csv-diff one.csv two.csv --key=id --show-unchanged
1 row changed
 id: 1
 age: "4" => "5"
 Unchanged:
 name: "Cleo"

You can use the --json option to get a machine-readable difference:

$ csv-diff one.csv two.csv --key=id --json
{
 "added": [
 {
 "id": "3",
 "name": "Bailey",
 "age": "1"
 }
 ],
 "removed": [
 {
 "id": "2",
 "name": "Pancakes",
 "age": "2"
 }
 ],
 "changed": [
 {
 "key": "1",
 "changes": {
 "age": [
 "4",
 "5"
 ]
 }
 }
 ],
 "columns_added": [],
 "columns_removed": []
}

You can specify additional keys to be displayed in the human-readable format using the --extra option:

--extra name "Python format string with {id} for variables"

For example, to output a link to https://news.ycombinator.com/latest?id={id} for each item with an ID, you could use this:

csv-diff one.csv two.csv --key=id \
 --extra latest "https://news.ycombinator.com/latest?id={id}"

These extras display something like this:

1 row changed
 id: 41459472
 points: "24" => "25"
 numComments: "5" => "6"
 extras:
 latest: https://news.ycombinator.com/latest?id=41459472

You can also import the Python library into your own code like so:

from csv_diff import load_csv, compare
diff = compare(
 load_csv(open("one.csv"), key="id"),
 load_csv(open("two.csv"), key="id")
)

diff will now contain the same data structure as the output in the --json example above.

If the columns in the CSV have changed, those added or removed columns will be ignored when calculating changes made to specific rows.

$ docker build -t csvdiff .

$ docker run --rm -v $(pwd):/files csvdiff

Suppose current directory contains two csv files : one.csv two.csv

$ docker run --rm -v $(pwd):/files csvdiff one.csv two.csv

• csvdiff is a "fast diff tool for comparing CSV files" - you may get better results from this than from csv-diff against larger files.