ERDDAP ERDDAPY

How to use erddapy

First of all, we need to instantiate the ERDDAP URL constructor for a server.

server

an ERDDAP server URL or an acronym for one of the builtin servers.

from erddapy import ERDDAP
import pandas as pd
e = ERDDAP(server="https://erddap.bcdc.no/erddap")

To explore the methods and attributes available in the ERDDAP object

Note: All the methods prefixed with get_ will return a valid ERDDAP URL for the requested response and options.

[method for method in dir(e) if not method.startswith("_")]

['auth', 'constraints', 'dataset_id', 'get_categorize_url', 'get_download_url', 'get_info_url', 'get_search_url', 'get_var_by_attr', 'protocol', 'relative_constraints', 'requests_kwargs', 'response', 'server', 'server_functions', 'to_iris', 'to_ncCF', 'to_pandas', 'to_xarray', 'variables']

To get help on method

help(e.get_search_url)

Help on method get_search_url in module erddapy.erddapy:

get_search_url(response: Union[str, NoneType] = None, search_for: Union[str, NoneType] = None, protocol: Union[str, NoneType] = None, items_per_page: int = 1000, page: int = 1, **kwargs) -> str method of erddapy.erddapy.ERDDAP instance

The search URL for the `server` endpoint provided.

Args:

search_for: "Google-like" search of the datasets' metadata.

- Type the words you want to search for, with spaces between the words.

ERDDAP will search for the words separately, not as a phrase.

- To search for a phrase, put double quotes around the phrase (for example, `"wind speed"`).

- To exclude datasets with a specific word, use `-excludedWord`.

- To exclude datasets with a specific phrase, use `-"excluded phrase"`

- Searches are not case-sensitive.

- You can search for any part of a word. For example, searching for `spee` will find datasets with `speed` and datasets with `WindSpeed`

- The last word in a phrase may be a partial word. For example, to find datasets from a specific website (usually the start of the datasetID), include (for example) `"datasetID=erd"` in your search.

response: default is HTML.

items_per_page: how many items per page in the return, default is 1000.

page: which page to display, default is the first page (1).

kwargs: extra search constraints based on metadata and/or coordinates ke/value.

metadata: `cdm_data_type`, `institution`, `ioos_category`, `keywords`, `long_name`, `standard_name`, and `variableName`.

coordinates: `minLon`, `maxLon`, `minLat`, `maxLat`, `minTime`, and `maxTime`.

Returns:

url: the search URL.

Then ERDDAP's users can:

• access to the list of all datasets available through this ERDDAP server
• access to the list of datasets by type (grid, tabular,..)

access to the list of all datasets available through this ERDDAP server

Here we use the get_search_url method

# show all datasets
url = e.get_search_url()
print(url)

https://erddap.icos-cp.eu/erddap/search/advanced.html?page=1&itemsPerPage=1000&protocol=(ANY)&cdm_data_type=(ANY)&institution=(ANY)&ioos_category=(ANY)&keywords=(ANY)&long_name=(ANY)&standard_name=(ANY)&variableName=(ANY)&minLon=(ANY)&maxLon=(ANY)&minLat=(ANY)&maxLat=(ANY)

we also specify the response attribute in our ERDDAP instance.

response

specifies the type of table data file that you want to download (default html). There are many response available, see the docs for griddap and tabledap respectively.

# show all datasets
e.response='csv'
url = e.get_search_url(search_for="all")
df = pd.read_csv(url)
df[['griddap','tabledap','Dataset ID']].head()

	griddap	tabledap	Dataset ID
0	NaN	https://erddap.icos-cp.eu/erddap/tabledap/allD...	allDatasets
1	NaN	https://erddap.icos-cp.eu/erddap/tabledap/icos...	icos26na20170409SocatEnhanced
2	NaN	https://erddap.icos-cp.eu/erddap/tabledap/icos...	icos26na20170421SocatEnhanced
3	NaN	https://erddap.icos-cp.eu/erddap/tabledap/icos...	icos26na20170430SocatEnhanced
4	NaN	https://erddap.icos-cp.eu/erddap/tabledap/icos...	icos26na20170511SocatEnhanced

access to the list of datasets by type (grid, tabular,..)

Here we use the get_search_url method, we also specify the response and protocol attributes in our ERDDAP instance

response

specifies the type of table data file that you want to download (default html).

protocol

choose between tabledap or griddap.

# show datasets by type
e.response='csv'
e.protocol='tabledap'
url = e.get_search_url()
df = pd.read_csv(url)
df[['griddap','tabledap','Dataset ID']].head()

	griddap	tabledap	Dataset ID
0	NaN	https://erddap.icos-cp.eu/erddap/tabledap/allD...	allDatasets
1	NaN	https://erddap.icos-cp.eu/erddap/tabledap/icos...	icos26na20170409SocatEnhanced
2	NaN	https://erddap.icos-cp.eu/erddap/tabledap/icos...	icos26na20170421SocatEnhanced
3	NaN	https://erddap.icos-cp.eu/erddap/tabledap/icos...	icos26na20170430SocatEnhanced
4	NaN	https://erddap.icos-cp.eu/erddap/tabledap/icos...	icos26na20170511SocatEnhanced

So ERDDAP's users can:

• access to the list of all datasets available through this ERDDAP server
• access to the list of datasets by type (grid, tabular,..)

But as user you probably don't want to use all datasets and you surely don't want to look in all of them to find which ones have the data you are interesting in.