snowexsql package¶

Submodules¶

snowexsql.analysis module¶

snowexsql.analysis.get_stats(data, logger=None)[source]¶

Calculate and report the typical stats on an numpy array.

Args:: data: Numpy array or Pandas Dataframe logger: Use a logger to report stats
Return:: result: Dictionary containing statistics

snowexsql.conversions module¶

Module contains all conversions used for manipulating data. This includes: filetypes, datatypes, etc. Many tools here will be useful for most end users of the database.

snowexsql.conversions.points_to_geopandas(results)[source]¶

Converts a successful query list into a geopandas data frame

Args:: results: List of PointData objects
Returns:: df: geopandas.GeoDataFrame instance

snowexsql.conversions.query_to_geopandas(query, engine, **kwargs)[source]¶

Convert a GeoAlchemy2 Query meant for postgis to a geopandas dataframe. Requires that a geometry column is included

Args:: query: GeoAlchemy2.Query Object engine: sqlalchemy engine
Returns:: df: geopandas.GeoDataFrame instance

snowexsql.conversions.query_to_pandas(query, engine, **kwargs)[source]¶

Convert a GeoAlchemy2 Query meant for postgis to a pandas dataframe.

Args:: query: Query Object engine: sqlalchemy engine
Returns:: df: pandas.DataFrame instance

snowexsql.conversions.raster_to_rasterio(session, rasters)[source]¶

Retrieve the numpy array of a raster by converting to a temporary file

Args:: session: sqlalchemy session object raster: list of geoalchemy2.types.Raster
Returns:: dataset: list of rasterio datasets

snowexsql.data module¶

Module contains all the data models for the database. Classes here actually represent tables where columns are mapped as attributed. Any class inheriting from Base is a real table in the database. This is called Object Relational Mapping in the sqlalchemy or ORM.

class snowexsql.data.ImageData(**kwargs)[source]¶

Bases: snowexsql.data.SnowData, snowexsql.data.Measurement, sqlalchemy.orm.decl_api.Base

Class representing the images table. This table holds all images/rasters

date¶

date_accessed¶

description¶

doi¶

id¶

instrument¶

observers¶

raster¶

site_name¶

time_created¶

time_updated¶

type¶

units¶

class snowexsql.data.LayerData(**kwargs)[source]¶

Bases: snowexsql.data.SingleLocationData, snowexsql.data.Measurement, sqlalchemy.orm.decl_api.Base

Class representing the layers table. This table holds all layers or profile data. Here a single data entry is a single value at depth in the snowpack and a single coordinate pair. e.g. SMP profiles, Hand hardness, temperature etc…

bottom_depth¶

comments¶

date¶

date_accessed¶

depth¶

doi¶

easting¶

elevation¶

flags¶

geom¶

id¶

instrument¶

latitude¶

longitude¶

northing¶

observers¶

pit_id¶

sample_a¶

sample_b¶

sample_c¶

site_id¶

site_name¶

time¶

time_created¶

time_updated¶

type¶

units¶

utm_zone¶

value¶

class snowexsql.data.Measurement[source]¶

Bases: object

Base Class providing attributes required for a measurement of any kind

instrument = Column(None, String(length=50), table=None)¶

observers = Column(None, String(length=100), table=None)¶

type = Column(None, String(length=50), table=None)¶

units = Column(None, String(length=50), table=None)¶

class snowexsql.data.PointData(**kwargs)[source]¶

Bases: snowexsql.data.SingleLocationData, snowexsql.data.Measurement, sqlalchemy.orm.decl_api.Base

Class representing the points table. This table holds all point data. Here a single data entry is a single coordinate pair with a single value e.g. snow depths

date¶

date_accessed¶

doi¶

easting¶

elevation¶

equipment¶

geom¶

id¶

instrument¶

latitude¶

longitude¶

northing¶

observers¶

site_id¶

site_name¶

time¶

time_created¶

time_updated¶

type¶

units¶

utm_zone¶

value¶

version_number¶

class snowexsql.data.SingleLocationData[source]¶

Bases: snowexsql.data.SnowData

Base class for points and profiles

easting = Column(None, Float(), table=None)¶

elevation = Column(None, Float(), table=None)¶

geom = Column(None, Geometry(geometry_type='POINT', from_text='ST_GeomFromEWKT', name='geometry'), table=None)¶

latitude = Column(None, Float(), table=None)¶

longitude = Column(None, Float(), table=None)¶

northing = Column(None, Float(), table=None)¶

site_id = Column(None, String(length=50), table=None)¶

time = Column(None, Time(timezone=True), table=None)¶

utm_zone = Column(None, Integer(), table=None)¶

class snowexsql.data.SiteData(**kwargs)[source]¶

Bases: snowexsql.data.SingleLocationData, sqlalchemy.orm.decl_api.Base

Table for storing pit site meta data, This table doesn’t represent any main data record but only support data for each site

air_temp¶

aspect¶

date¶

date_accessed¶

doi¶

easting¶

elevation¶

geom¶

ground_condition¶

ground_roughness¶

ground_vegetation¶

id¶

latitude¶

longitude¶

northing¶

pit_id¶

precip¶

site_id¶

site_name¶

site_notes¶

sky_cover¶

slope_angle¶

time¶

time_created¶

time_updated¶

total_depth¶

tree_canopy¶

utm_zone¶

vegetation_height¶

weather_description¶

wind¶

class snowexsql.data.SnowData[source]¶

Bases: object

Base class for which all data will have these attributes

date = Column(None, Date(), table=None)¶

date_accessed = Column(None, Date(), table=None)¶

doi = Column(None, String(length=50), table=None)¶

id = Column(None, Integer(), table=None, primary_key=True, nullable=False)¶

site_name = Column(None, String(length=250), table=None)¶

time_created = Column(None, DateTime(timezone=True), table=None, server_default=DefaultClause(<sqlalchemy.sql.functions.now at 0x7f30eef53190; now>, for_update=False))¶

time_updated = Column(None, DateTime(timezone=True), table=None, onupdate=ColumnDefault(<sqlalchemy.sql.functions.now at 0x7f30eef533d0; now>))¶

snowexsql.db module¶

This module contains tool used directly regarding the database. This includes getting a session, initializing the database, getting table attributes, etc.

snowexsql.db.get_db(db_str, credentials=None, return_metadata=False)[source]¶

Returns the DB engine, MetaData, and session object

Args:

db_str: Just the name of the database credentials: Path to a json file containing username and password for the database return_metadata: Boolean indicating whether the metadata object is

being returned, useful only for developers

Returns:

tuple: engine - sqlalchemy Engine object for directly sending

querys to the DB

session - sqlalchemy Session Object for using object: relational mapping (ORM)
metadata (optional) - sqlalchemy MetaData object for: modifying the database

snowexsql.db.get_table_attributes(DataCls)[source]¶: Returns a list of all the table columns to be used for each entry

snowexsql.db.initialize(engine)[source]¶: Creates the original database from scratch, currently only for point data

snowexsql.functions module¶

This module holds all PostGIS functions that have not been mapped yet for use with ORM. Many function already exist in GeoAlchemy.functions module

class snowexsql.functions.ST_Clip(*args, **kwargs)[source]¶