Source code for pycif.utils.classes.obsparsers

#!/usr/bin/env python
# -*- coding: utf-8 -*-
import glob
import os
from types import MethodType

import pandas as pd

from ...utils.check import errclass as error
from logging import info
from .baseclass import Plugin
from .setup import Setup


class ObsParser(Plugin):
    """Class for handling time series parsing from different data providers
    and data file formats.

    """

    def initiate_template(self):
        super(ObsParser, self).initiate_template(
            plg_type="obsparser",
            default_functions={
                "do_parse": True, "parse_multiple_files": True
                
            }
        )

    @classmethod
    def get_parser(cls, plg):
        """Get the correct Parser for a provider and file_format_id

        Args:
            provider (str):  provider of the input file
            file_format_id (str): name of the type of file with a given format

        Returns:
            Parser: Parser for provider and file_format_id
        """
        parser = cls.load_registered(
            plg.provider, plg.format, "obsparser", plg_orig=plg
        )

        # Loading the parser
        toload = Setup(parser=parser)
        Setup.load_setup(toload, level=1)

        return toload.parser

    @classmethod
    def register_parser(cls, provider, file_format_id, parse_module, **kwargs):
        """Register a parsing function for provider and format with default
        options

        Args:
            provider (str):  provider of the input file
            file_format_id (str): name of the type of file with a given format
            parse_module (Module):
                    returns file content
                    as pandas.DataFrame df[obssite_id, parameter]
            **kwargs: default options for parse_function

        Notes:
            The parse_function signature is the same as
            the :py:func:`Parser.parse_file`
        """
        super(ObsParser, cls).register_plugin(
            provider, file_format_id, parse_module, plugin_type="obsparser", **kwargs
        )

    def parse_file(self, obs_file, **kwargs):
        """This function does the parsing (and post processing if necessary).

        Args:
            obs_file (str): path to input file

        Keyword Args:
            encoding (str): Encoding of input files
            freq (str): frequency after resampling
                        see `Offset Aliases`_ for valid strings
            src_freq (str):
                        explicit setting of the frequency in the input file
                        shouldn't be necessary

        Returns:
            pandas.DataFrame: renamed, shifted, resampled
            Dataframe df[obssite_id, parameter] with t as index
        """

        df = self.do_parse(obs_file, **kwargs)

        # Removing rows with only NaNs
        df = df.dropna(axis=0, how="all")

        # Checking that the returned dataframe has all required columns
        if self.check_df(df, **kwargs):
            return df

    def parse_multiple_files(self, **kwargs):
        """Parses multiple files specified by a glob pattern and stores the
        content into a datastore.

        Args:
            self: the plugin with its describing arguments (in particular dir_obs)

        Returns:
            dict: {obs_file} = df[obssite_id, parameter]

        Note:
            By default, the function calls `self.parse_file`, which filters out
            NaNs and check that all required columns are available.


        """

        dfs = {}

        info("Reading files in " + self.dir_obs)
        for obs_file in sorted(glob.glob(self.dir_obs + "*")):
            try:
                dfs[os.path.basename(obs_file)] = self.parse_file(
                    obs_file, **kwargs
                )

            except error.PluginError as e:
                info(
                    "{} was not loaded for the following reason".format(
                        obs_file
                    )
                )
                info(e)

        if dfs != {}:
            return pd.concat(list(dfs.values()))
        else:
            return pd.DataFrame({})

    @staticmethod
    def check_df(df, **kwargs):
        """Check that all required columns have been loaded

        :param df:
        :param kwargs:
        :return:
        """

        reqcols = ["station", "network", "parameter", "duration", "obserror"]
        cols = df.columns
        for c in reqcols:
            meta = "metadata"
            if c == "obserror":
                meta = "maindata"

            if c not in cols and (meta, c) not in cols:
                towrite = """
                    {} was not returned in the dataframe
                    Please check your parser definition
                    """.format(
                    c
                )
                raise error.PluginError(towrite)

        return True