Many PV modeling applications require irradiance and meteorological datasets as the inputs to a PV system model. These weather datasets are available from many sources and in many formats. The :pypvlib.iotools module contains functions to retrieve and import these datasets in a form that is convenient to use with the rest of pvlib.
Although there are some exceptions, the :pypvlib.iotools functions provide a uniform interface for reading data files in many common formats. Specifically, :pypvlib.iotools functions usually return two objects: a :pypandas.DataFrame of the actual dataset and, plus a metadata dictionary. Most :pypvlib.iotools functions also have a map_variables parameter to automatically translate the column names used in the data file (which vary widely across datasets) into standard pvlib names (see variables_style_rules). Typical usage looks like this:
df, metadata = pvlib.iotools.function(..., map_variables=True)Most :pypvlib.iotools functions work with time series datasets. In that case, the returned df DataFrame has a datetime index, localized to the appropriate time zone where possible. The metadata dictionary varies based on the function/dataset being used.
For the full list of available :pypvlib.iotools functions, see iotools.
Some weather data file formats have internal structure that requires more than just a call to :pypandas.read_csv. pvlib provides functions for reading files in many of these formats. Functions that read and parse files in a particular format have names that begin with read_: :py~pvlib.iotools.read_tmy3, :py~pvlib.iotools.read_epw, and so on.
Several :pypvlib.iotools functions access the internet to fetch data from external web APIs. For example, :py~pvlib.iotools.get_pvgis_hourly downloads data from PVGIS's webservers and returns it as a python variable. Functions that retrieve data from the internet have names that begin with get_: :py~pvlib.iotools.get_bsrn, :py~pvlib.iotools.get_psm3, :py~pvlib.iotools.get_pvgis_tmy, and so on.
Some of these data providers require registration. In those cases, your access credentials must be passed as parameters to the function. See the individual function documentation pages for details.