siphon.http_util
Utility code to support making requests using HTTP.
- class siphon.http_util.DataQuery[source]
Represent a query for data from a THREDDS server.
This object provides a clear API to formulate a query for data, including a spatial query, a time query, and possibly some variables or other parameters. These objects provide a dictionary-like interface, (
itemsand__iter__) sufficient to be passed to functions expecting a dictionary representing a URL query. Instances of this object can also be turned into a string, which will yield a properly escaped string for a URL.- add_query_parameter(**kwargs)[source]
Add arbitrary query element (name=value) to the request.
This modifies the query in-place, but returns self so that multiple queries can be chained together on one line.
- Parameters:
kwargs – Names and values of parameters to add to the query
- Returns:
self – Returns self for chaining calls
- Return type:
- all_times()[source]
Add a request for all times to the query.
This adds a request for all times (temporal=all). This modifies the query in-place, but returns self so that multiple queries can be chained together on one line.
This replaces any existing temporal queries that have been set.
- Returns:
self – Returns self for chaining calls
- Return type:
- items()[source]
Return the various name=value pairs that compose the query.
- Returns:
items – Sequence of tuples of name, value representing the query.
- Return type:
iterator
- lonlat_box(west, east, south, north)[source]
Add a latitude/longitude bounding box to the query.
This adds a request for a spatial bounding box, bounded by (‘north’, ‘south’) for latitude and (‘east’, ‘west’) for the longitude. This modifies the query in-place, but returns self so that multiple queries can be chained together on one line.
This replaces any existing spatial queries that have been set.
- Parameters:
west (float) – The bounding longitude to the west, in degrees east of the prime meridian
east (float) – The bounding longitude to the east, in degrees east of the prime meridian
south (float) – The bounding latitude to the south, in degrees north of the equator
north (float) – The bounding latitude to the north, in degrees north of the equator
- Returns:
self – Returns self for chaining calls
- Return type:
- lonlat_point(lon, lat)[source]
Add a latitude/longitude point to the query.
This adds a request for a (lon, lat) point. This modifies the query in-place, but returns self so that multiple queries can be chained together on one line.
This replaces any existing spatial queries that have been set.
- time(time)[source]
Add a request for a specific time to the query.
This modifies the query in-place, but returns self so that multiple queries can be chained together on one line.
This replaces any existing temporal queries that have been set.
- Parameters:
time (datetime.datetime) – The time to request
- Returns:
self – Returns self for chaining calls
- Return type:
- time_range(start, end)[source]
Add a request for a time range to the query.
This modifies the query in-place, but returns self so that multiple queries can be chained together on one line.
This replaces any existing temporal queries that have been set.
- Parameters:
start (datetime.datetime) – The start of the requested time range
end (datetime.datetime) – The end of the requested time range
- Returns:
self – Returns self for chaining calls
- Return type:
- class siphon.http_util.HTTPEndPoint(url)[source]
An object representing an endpoint on a server that is accessed using HTTP.
This provides a simple way to point to a URL, formulate appropriate queries and validate them, parse metadata as appropriate, and parse returns from requests.
- get(path, params=None)[source]
Make a GET request, optionally including a parameters, to a path.
The path of the request is the full URL.
- Parameters:
- Returns:
resp – The server’s response to the request
- Return type:
- Raises:
HTTPError – If the server returns anything other than a 200 (OK) code
- get_path(path, query=None)[source]
Make a GET request, optionally including a query, to a relative path.
The path of the request includes a path on top of the base URL assigned to the endpoint.
- Parameters:
- Returns:
resp – The server’s response to the request
- Return type:
- get_query(query)[source]
Make a GET request, including a query, to the endpoint.
The path of the request is to the base URL assigned to the endpoint.
- Parameters:
query (DataQuery) – The query to pass when making the request
- Returns:
resp – The server’s response to the request
- Return type:
- query()[source]
Create a new query object.
Returns a new
DataQueryinstance appropriate for this endpoint.The default implementation returns a
DataQueryinstance. Subclasses can override to return a subclass specific to this endpoint.- Returns:
q – A new query object
- Return type:
- url_path(path)[source]
Assemble the full url to a path.
Given a path relative to the base URL, assemble the full URL.
- Parameters:
path (str) – The path, relative to the endpoint
- Returns:
url – The full URL to path
- Return type:
See also
- validate_query(query)[source]
Validate a query.
Determines whether a query is well-formed. This includes checking for all required parameters, as well as checking parameters for valid values.
The default implementation does nothing. It is presumed that subclasses implement this to do more detailed checking as appropriate.
- class siphon.http_util.HTTPSessionManager[source]
Manage the creation of sessions for HTTP access.
- create_session()[source]
Create a new HTTP session with our user-agent set.
- Returns:
session – The created session
- Return type:
See also
- set_session_options(**kwargs)[source]
Set options for created session instances.
Takes keyword arguments and sets them as attributes on the returned
requests.Sessioninstance.See also
- urlopen(url, decompress=False, **kwargs)[source]
GET a file-like object for a URL using HTTP.
This is a thin wrapper around
requests.Session.get()that returns a file-like object wrapped around the resulting content.- Parameters:
url (str) – The URL to request
kwargs – Additional keyword arguments to pass to
requests.Session.get().
- Returns:
fobj – A file-like interface to the content in the response
- Return type:
file-like object
See also