https://github.com/ckan/ckanapi-exporter
Export dataset metadata from CKAN to Excel-compatible CSV
https://github.com/ckan/ckanapi-exporter
Last synced: 9 months ago
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Export dataset metadata from CKAN to Excel-compatible CSV
- Host: GitHub
- URL: https://github.com/ckan/ckanapi-exporter
- Owner: ckan
- License: agpl-3.0
- Created: 2014-10-22T19:58:16.000Z (about 11 years ago)
- Default Branch: master
- Last Pushed: 2019-03-30T07:31:38.000Z (almost 7 years ago)
- Last Synced: 2025-04-18T04:48:46.655Z (9 months ago)
- Language: Python
- Size: 40 KB
- Stars: 25
- Watchers: 9
- Forks: 10
- Open Issues: 4
-
Metadata Files:
- Readme: README.markdown
- License: LICENSE
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ckanapi-exporter
================
An API client (usable as a command-line script or as a Python library) for
exporting dataset metadata from CKAN sites to Excel-compatible CSV files.
Installation
------------
To install run:
pip install ckanapi-exporter
Usage
-----
```bash
ckanapi-exporter --url 'https://demo.ckan.org' \
--column "Title" --pattern '^title$' > output.csv
```
This searches each dataset on demo.ckan.org for fields matching the
[regular expression](https://docs.python.org/2/howto/regex.html#regex-howto)
`^title$` (the `--pattern` argument) and puts the values into a
column called "Title" in the CSV file (the `--column` argument). It'll create
an `output.csv` file something like this:
Title
Senior Salaries Information
Demo Data for Open Data in 1 Day - Spending Over £500
UK Cat Burglaries
...
You can add as many columns as you want: just add a `--column` and a
`--pattern` argument for each column. The title of the column in the CSV file
can be anything you want - it doesn't have to match the name of the field in
CKAN. Let's add a second column titled "Rights" that contains the
`license_title` fields from the datasets:
```bash
ckanapi-exporter --url 'https://demo.ckan.org' \
--column "Title" --pattern '^title$' \
--column "Rights" --pattern '^license_title$' > output.csv
```
Title
Rights
Senior Salaries Information
Creative Commons Attribution
Demo Data for Open Data in 1 Day - Spending Over £500
Creative Commons CCZero
UK Cat Burglaries
UK Open Government Licence (OGL)
...
...
### API Parameters
The ckanapi-exporter calls the [`package_search`](http://docs.ckan.org/en/latest/api/index.html#ckan.logic.action.get.package_search)
API action and you can pass in related query parameters by using the `--params`
argument and passing in a string formated as a dictionary. Each key: value pair
represents a query passed to the API call.
For example if you wanted to only export datasets between a date range you can
pass in the `fq` (filtered query) parameter and use `metadata_created` to filter
the results.
```bash
ckanapi-exporter --url 'https://demo.ckan.org' \
--params "{'fq':'metadata_created:[2017-01-01T00:00:00Z TO 2017-01-31T23:59:99.999Z]'}" \
--column "Title" --pattern '^title$' \
--column "Rights" --pattern '^license_title$' > output.csv
```
### Transformations
You can apply certain transformations to the values from the datasets.
For example, let's add a third column with the first 50 characters of each
dataset's description (the `notes` field in the CKAN API):
```bash
ckanapi-exporter --url 'https://demo.ckan.org' \
--column "Title" --pattern '^title$' \
--column "Rights" --pattern '^license_title$' \
--column "Description" --pattern '^notes$' --max-length 50 > output.csv
```
Title
Rights
Description
Senior Salaries Information
Creative Commons Attribution
Demo information about senior salaries from 11/04/
Demo Data for Open Data in 1 Day - Spending Over £500
Creative Commons CCZero
Data on spending over £500 generated for Open Data
UK Cat Burglaries
UK Open Government Licence (OGL)
A record of cat burgalries, listing the cat names,
...
...
...
### Exporting Resource Fields
Let's add a column containing the formats of each datasets' resources:
```bash
ckanapi-exporter --url 'https://demo.ckan.org' \
--column "Title" --pattern '^title$' \
--column "Rights" --pattern '^license_title$' \
--column "Description" --pattern '^notes$' --max-length 50 \
--column Formats --pattern '^resources$' '^format$' > output.csv
```
This time the pattern has two arguments: `--pattern '^resources$' '^format$'`.
This means find the "resources" field of each dataset and then find the
"format" field of each resource. When a dataset has more than one resource
the formats will be combined into a quoted, comma-separated list in a single
table cell. It'll create a CSV file something like this:
Title
Rights
Description
Formats
Senior Salaries Information
Creative Commons Attribution
Demo information about senior salaries from 11/04/
XLSX, CSV
Demo Data for Open Data in 1 Day - Spending Over £500
Creative Commons CCZero
Data on spending over £500 generated for Open Data
CSV, CSV, CSV, CSV
UK Cat Burglaries
UK Open Government Licence (OGL)
A record of cat burgalries, listing the cat names,
JPEG, CSV, CSV
...
...
...
...
CSV is repeated a lot because lots of the datasets have multiple CSV resources.
You can add the `--deduplicate` option to the column to remove the duplication:
```bash
ckanapi-exporter --url 'https://demo.ckan.org' \
--column "Title" --pattern '^title$' \
--column "Rights" --pattern '^license_title$' \
--column "Description" --pattern '^notes$' --max-length 50 \
--column Formats --pattern '^resources$' '^format$' --deduplicate \
> output.csv
```
Title
Rights
Description
Formats
Senior Salaries Information
Creative Commons Attribution
Demo information about senior salaries from 11/04/
XLSX, CSV
Demo Data for Open Data in 1 Day - Spending Over £500
Creative Commons CCZero
Data on spending over £500 generated for Open Data
CSV
UK Cat Burglaries
UK Open Government Licence (OGL)
A record of cat burgalries, listing the cat names,
JPEG, CSV
...
...
...
...
### Exporting Dataset Extras
Let's add a column with the values of the "Next Update" extra from each
dataset. Dataset publishers have been inconsistent with naming this column,
it's sometimes "Next Update" and sometimes "next update", "Next update day",
"Next Update Time" etc. We'll use a regular expression that matches all of
these possible names and combine them into a single "Next Update" column:
```bash
ckanapi-exporter --url 'https://demo.ckan.org' \
--column "Title" --pattern '^title$' \
--column "Rights" --pattern '^license_title$' \
--column "Description" --pattern '^notes$' --max-length 50 \
--column Formats --pattern '^resources$' '^format$' --deduplicate \
--column "Next Update" --pattern '^extras$' '^next update.*' --unique \
> output.csv
```
The two-part pattern `'^extras$' '^next update.*'` means to look in the
"extras" field of each dataset for extras whose name matches
`^next update.*`. We're expecting each dataset to have only one matching
extra so we add the `--unique` argument which will crash if a dataset has more
than one extra matching the pattern.
By default patterns are matched case-insensitively and whitespace is stripped
from field names before matching. To match case-sensitively and without
stripping whitespace add `--case-sensitive --strip false` to the column.
We can also find multiple extras and combine them into a single column.
For example, let's say our datasets have a "contributor" extra
(sometimes spelled "contributor", sometimes "Contributor"). Some datasets have
multiple extras named "Contributor 1", "Contributor 2" etc. We can find all of
these contributor extras and combine them into a single quoted, comma-separated
list with a pattern like this:
--column Contributors --pattern '^extras$' '^contributor.*'
### Using a columns.json File
You can specify your columns in a `columns.json` file instead of on the command
line. Here's an example of the format:
```json
{
"Data Owner": {
"pattern": "^author$",
"unique": true,
"case_sensitive": true
},
"Delivery Unit": {
"pattern": ["^extras$", "^Delivery Unit$"],
"unique": true
},
"Contributor": {
"pattern": ["^extras$", "^Contributor.*"]
},
"Description": {
"pattern": "^notes$",
"unique": true,
"case_sensitive": true,
"max_length": 255
},
"Format": {
"pattern": ["^resources$", "^format$"],
"case_sensitive": true,
"deduplicate": true
}
}
```
Then tell ckanapi-exporter to read the column options from this file instead of
giving them on the command line:
```bash
ckanapi-exporter --url 'https://demo.ckan.org' --columns columns.json > output.csv
```
For a working example `columns.json` file that you can use against demo.ckan.org,
see [test_columns.json](ckanapi_exporter/test_columns.json).
ckanapi-exporter is a thin wrapper around
[losser](https://github.com/ckan/losser), hooking it up to the CKAN API.
For more documentation of the filtering and transforming options run
`ckanapi-exporter --help` or read losser's docs.
Using as a Python Library
-------------------------
You can also import ckanapi-exporter in Python and use it from your CKAN API
client or plugin:
```python
import ckanapi_exporter.exporter as exporter
csv_string = exporter.export('https://demo.ckan.org', 'columns.json')
```
Returns a UTF8-encoded string.
The second argument can be either the filename of the columns.json file as a
string, or a list of dictionaries (equivalent to the contents of columns.json
file after loading the JSON).
Development
-----------
To install for development, create and activate a Python virtual environment
then do:
```bash
git clone https://github.com/ckan/ckanapi-exporter.git
cd ckanapi-exporter
python setup.py develop
pip install -r dev-requirements.txt
```
To run the tests do:
nosetests