Package: ckanapi-exporter
[![Build Status](https://travis-ci.org/ckan/ckanapi-exporter.svg)](https://travis-ci.org/ckan/ckanapi-exporter)[![Coverage Status](https://img.shields.io/coveralls/ckan/ckanapi-exporter.svg)](https://coveralls.io/r/ckan/ckanapi-exporter)[![Latest Version](https://img.shields.io/pypi/v/ckanapi-exporter.svg)](https://pypi.python.org/pypi/ckanapi-exporter/)[![Supported Python versions](https://img.shields.io/pypi/pyversions/ckanapi-exporter.svg)](https://pypi.python.org/pypi/ckanapi-exporter/)[![Development Status](https://img.shields.io/pypi/status/ckanapi-exporter.svg)](https://pypi.python.org/pypi/ckanapi-exporter/)[![License](https://img.shields.io/pypi/l/ckanapi-exporter.svg)](https://pypi.python.org/pypi/ckanapi-exporter/)ckanapi-exporter================An API client (usable as a command-line script or as a Python library) forexporting dataset metadata from CKAN sites to Excel-compatible CSV files.Installation------------To install run:pip install ckanapi-exporterUsage-----```bashckanapi-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 acolumn called "Title" in the CSV file (the `--column` argument).  It'll createan `output.csv` file something like this:<table><tr><th>Title</th></tr><tr><td>Senior Salaries Information</td></tr><tr><td>Demo Data for Open Data in 1 Day - Spending Over £500</td></tr><tr><td>UK Cat Burglaries</td></tr><tr><td>...</td></tr></table>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 filecan be anything you want - it doesn't have to match the name of the field inCKAN. Let's add a second column titled "Rights" that contains the`license_title` fields from the datasets:```bashckanapi-exporter --url 'https://demo.ckan.org' \--column "Title" --pattern '^title$' \--column "Rights" --pattern '^license_title$' > output.csv```<table><tr><th>Title</th><th>Rights</th></tr><tr><td>Senior Salaries Information</td><td>Creative Commons Attribution</td></tr><tr><td>Demo Data for Open Data in 1 Day - Spending Over £500</td><td>Creative Commons CCZero</td></tr><tr><td>UK Cat Burglaries</td><td>UK Open Government Licence (OGL)</td></tr><tr><td>...</td><td>...</td></tr></table>### API ParametersThe 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 pairrepresents a query passed to the API call.For example if you wanted to only export datasets between a date range you canpass in the `fq` (filtered query) parameter and use `metadata_created` to filterthe results.```bashckanapi-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```### TransformationsYou can apply certain transformations to the values from the datasets.For example, let's add a third column with the first 50 characters of eachdataset's description (the `notes` field in the CKAN API):```bashckanapi-exporter --url 'https://demo.ckan.org' \--column "Title" --pattern '^title$' \--column "Rights" --pattern '^license_title$' \--column "Description" --pattern '^notes$' --max-length 50 > output.csv```<table><tr><th>Title</th><th>Rights</th><th>Description</th></tr><tr><td>Senior Salaries Information</td><td>Creative Commons Attribution</td><td>Demo information about senior salaries from 11/04/</td></tr><tr><td>Demo Data for Open Data in 1 Day - Spending Over £500</td><td>Creative Commons CCZero</td><td>Data on spending over £500 generated for Open Data</td></tr><tr><td>UK Cat Burglaries</td><td>UK Open Government Licence (OGL)</td><td>A record of cat burgalries, listing the cat names,</td></tr><tr><td>...</td><td>...</td><td>...</td></tr></table>### Exporting Resource FieldsLet's add a column containing the formats of each datasets' resources:```bashckanapi-exporter --url 'https://demo.ckan.org' \--column "Title" --pattern '^title$' \--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 resourcethe formats will be combined into a quoted, comma-separated list in a singletable cell. It'll create a CSV file something like this:<table><tr><th>Title</th><th>Rights</th><th>Description</th><th>Formats</th></tr><tr><td>Senior Salaries Information</td><td>Creative Commons Attribution</td><td>Demo information about senior salaries from 11/04/</td><td>XLSX, CSV</td></tr><tr><td>Demo Data for Open Data in 1 Day - Spending Over £500</td><td>Creative Commons CCZero</td><td>Data on spending over £500 generated for Open Data</td><td>CSV, CSV, CSV, CSV</td></tr><tr><td>UK Cat Burglaries</td><td>UK Open Government Licence (OGL)</td><td>A record of cat burgalries, listing the cat names,</td><td>JPEG, CSV, CSV</td></tr><tr><td>...</td><td>...</td><td>...</td><td>...</td></tr></table>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:```bashckanapi-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$' --deduplicate \> output.csv```<table><tr><th>Title</th><th>Rights</th><th>Description</th><th>Formats</th></tr><tr><td>Senior Salaries Information</td><td>Creative Commons Attribution</td><td>Demo information about senior salaries from 11/04/</td><td>XLSX, CSV</td></tr><tr><td>Demo Data for Open Data in 1 Day - Spending Over £500</td><td>Creative Commons CCZero</td><td>Data on spending over £500 generated for Open Data</td><td>CSV</td></tr><tr><td>UK Cat Burglaries</td><td>UK Open Government Licence (OGL)</td><td>A record of cat burgalries, listing the cat names,</td><td>JPEG, CSV</td></tr><tr><td>...</td><td>...</td><td>...</td><td>...</td></tr></table>### Exporting Dataset ExtrasLet's add a column with the values of the "Next Update" extra from eachdataset. Dataset publishers have been inconsistent with naming this column,it's sometimes "Next Update" and sometimes "next update", "Next update day","Next Update Time" etc. We'll use a regular expression that matches all ofthese possible names and combine them into a single "Next Update" column:```bashckanapi-exporter --url 'https://demo.ckan.org' \--column "Title" --pattern '^title$' \--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 matchingextra so we add the `--unique` argument which will crash if a dataset has morethan one extra matching the pattern.By default patterns are matched case-insensitively and whitespace is strippedfrom field names before matching. To match case-sensitively and withoutstripping 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 havemultiple extras named "Contributor 1", "Contributor 2" etc. We can find all ofthese contributor extras and combine them into a single quoted, comma-separatedlist with a pattern like this:--column Contributors --pattern '^extras$' '^contributor.*'### Using a columns.json FileYou can specify your columns in a `columns.json` file instead of on the commandline. Here's an example of the format:```json{"Data Owner": {"pattern": "^author$","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 ofgiving them on the command line:```bashckanapi-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 APIclient or plugin:```pythonimport ckanapi_exporter.exporter as exportercsv_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 astring, or a list of dictionaries (equivalent to the contents of columns.jsonfile after loading the JSON).Development-----------To install for development, create and activate a Python virtual environmentthen do:```bashgit clone https://github.com/ckan/ckanapi-exporter.gitcd ckanapi-exporterpython setup.py developpip install -r dev-requirements.txt```To run the tests do:nosetests