Source code for pyDataverse.utils

# !/usr/bin/env python
# -*- coding: utf-8 -*-
"""Dataverse utility functions."""
import csv
import json


def json_to_dict(data):
    """Convert JSON to a dict().

    See more about the json module at
    https://docs.python.org/3.5/library/json.html

    Parameters
    ----------
    data : string
        Data as a json-formatted string.

    Returns
    -------
    dict
        Data as Python Dictionary.

    """
    try:
        return json.loads(data)
    except Exception as e:
        raise e


def dict_to_json(data):
    """Convert dict() to JSON-formatted string.

    See more about the json module at
    https://docs.python.org/3.5/library/json.html

    Parameters
    ----------
    data : dict
        Data as Python Dictionary.

    Returns
    -------
    string
        Data as a json-formatted string.

    """
    try:
        return json.dumps(data, ensure_ascii=True, indent=2)
    except Exception as e:
        raise e


def read_file(filename, mode='r'):
    """Read in a file.

    Parameters
    ----------
    filename : string
        Filename with full path.
    mode : string
        Read mode of file. Defaults to `r`. See more at
        https://docs.python.org/3.5/library/functions.html#open

    Returns
    -------
    string
        Returns data as string.

    """
    try:
        with open(filename, mode) as f:
            data = f.read()
        return data
    except IOError:
        print('An error occured trying to read the file {}.'.format(filename))
    except Exception as e:
        raise e


def write_file(filename, data, mode='w'):
    """Write data in a file.

    Parameters
    ----------
    filename : string
        Filename with full path.
    data : string
        Data to be stored.
    mode : string
        Read mode of file. Defaults to `w`. See more at
        https://docs.python.org/3.5/library/functions.html#open

    """
    try:
        with open(filename, mode) as f:
            f.write(data)
    except IOError:
        print('An error occured trying to write the file {}.'.format(filename))
    except Exception as e:
        raise e


def read_file_json(filename):
    """Read in a json file.

    See more about the json module at
    https://docs.python.org/3.5/library/json.html

    Parameters
    ----------
    filename : string
        Filename with full path.

    Returns
    -------
    dict
        Data as a json-formatted string.

    """
    try:
        return json_to_dict(read_file(filename, 'r'))
    except Exception as e:
        raise e


def write_file_json(filename, data, mode='w'):
    """Write data to a json file.

    Parameters
    ----------
    filename : string
        Filename with full path.
    data : dict
        Data to be written in the json file.
    mode : string
        Write mode of file. Defaults to `w`. See more at
        https://docs.python.org/3/library/functions.html#open

    """
    write_file(filename, dict_to_json(data), mode)


def read_file_csv(filename):
    """Read in CSV file.

    See more at `csv.reader() <https://docs.python.org/3.5/library/csv.html>`_.

    Parameters
    ----------
    filename : string
        Full filename with path of file.

    Returns
    -------
    reader
        Reader object, which can be iterated over.

    """
    try:
        with open(filename, newline='') as csvfile:
            return csv.reader(csvfile, delimiter=',', quotechar='"')
    except Exception as e:
        raise e
    finally:
        csvfile.close()


def read_csv_to_dict(filename):
    """Read in csv file and convert it into a list of dicts.

    This offers an easy import functionality of csv files with dataset metadata.

    Assumptions:
    1) The header rows contains the column names, named after Dataverse's
    dataset attribute standard naming convention.
    2) One row contains one dataset

    After the import, the created dict then can directly be used to set
    Dataset() attributes via ``Dataset.set(data)``.

    Parameters
    ----------
    filename : string
        Filename with full path.

    Returns
    -------
    list
        List with one dict per row (=dataset). The keys of the dicts are named
        after the columen names, which must be named after the Dataverse
        dataset metadata naming convention.

    """
    reader = csv.DictReader(open(filename), 'r')
    data = []
    for row in reader:
        data.append(dict(row))
    return data