models

formatting.models

Classes

Classification

Bases: PermissionsBase

Contains instructions on how to classify the data into a specific variable.

In particular, it links a format to a variable, and provides the column indices for the value, maximum, and minimum columns, as well as the validator columns. It also contains information on whether the data is accumulated, incremental, and the resolution of the data.

Attributes:

Name	Type	Description
cls_id	AutoField	Primary key.
format	ForeignKey	The format of the data file.
variable	ForeignKey	The variable to which the data belongs.
value	PositiveSmallIntegerField	Index of the value column, starting in 0.
maximum	PositiveSmallIntegerField	Index of the maximum value column, starting in 0.
minimum	PositiveSmallIntegerField	Index of the minimum value column, starting in 0.
value_validator_column	PositiveSmallIntegerField	Index of the value validator column, starting in 0.
value_validator_text	CharField	Value validator text.
maximum_validator_column	PositiveSmallIntegerField	Index of the maximum value validator column, starting in 0.
maximum_validator_text	CharField	Maximum value validator text.
minimum_validator_column	PositiveSmallIntegerField	Index of the minimum value validator column, starting in 0.
minimum_validator_text	CharField	Minimum value validator text.
accumulate	PositiveSmallIntegerField	If set to a number of minutes, the data will be accumulated over that period.
resolution	DecimalField	Resolution of the data. Only used if it is to be accumulated.
incremental	BooleanField	Whether the data is an incremental counter. If it is, any value below the previous one will be removed.
decimal_comma	BooleanField	Whether the data uses a comma as a decimal separator.

Functions

__str__()

Return the string representation of the object.

Source code in formatting/models.py

def __str__(self) -> str:
    """Return the string representation of the object."""
    return str(self.cls_id)

clean()

Validate the model instance.

It checks that the column indices are different, and that the accumulation period is greater than zero if it is set. It also checks that the resolution is set if the data is accumulated.

Source code in formatting/models.py

def clean(self) -> None:
    """Validate the model instance.

    It checks that the column indices are different, and that the accumulation
    period is greater than zero if it is set. It also checks that the resolution is
    set if the data is accumulated.
    """
    if self.accumulate and self.resolution is None:
        raise ValidationError(
            {
                "resolution": "The resolution must be set if the data is "
                "accumulated."
            }
        )

    col_names = [
        "value",
        "maximum",
        "minimum",
        "value_validator_column",
        "maximum_validator_column",
        "minimum_validator_column",
    ]
    unique = defaultdict(list)
    for name in col_names:
        if getattr(self, name) is not None:
            unique[getattr(self, name)].append(name)
    for _, names in unique.items():
        if len(names) != 1:
            msg = "The columns must be different."
            raise ValidationError({field: msg for field in names})

get_absolute_url()

Get the absolute URL of the object.

Source code in formatting/models.py

def get_absolute_url(self) -> str:
    """Get the absolute URL of the object."""
    return reverse("format:classification_detail", kwargs={"pk": self.pk})

Date

Bases: PermissionsBase

Date format.

Format string for the date column. It is used to parse the date column in the data file. The format string must be compatible with the datetime module in Python. See the datetime documentation for more information on valid format codes.

Attributes:

Name	Type	Description
date_id	AutoField	Primary key.
date_format	CharField	The format string for the date column in human readable form, eg. DD-MM-YYYY.
code	CharField	The code used to parse the date column, eg. %d-%m-%Y.

Functions

__str__()

Return the string representation of the object.

Source code in formatting/models.py

def __str__(self) -> str:
    """Return the string representation of the object."""
    return str(self.date_format)

get_absolute_url()

Get the absolute URL of the object.

Source code in formatting/models.py

def get_absolute_url(self) -> str:
    """Get the absolute URL of the object."""
    return reverse("format:date_detail", kwargs={"pk": self.pk})

Delimiter

Bases: PermissionsBase

Delimiter between columns in the data file.

One or more characters that separate columns in a text file. The most common values are ,, ;, and \t (tab).

Attributes:

Name	Type	Description
delimiter_id	AutoField	Primary key.
name	CharField	The name of the delimiter. eg. comma, semicolon, tab.
character	CharField	The character used as a delimiter. eg. ,, ;, \t.

Functions

__str__()

Return the string representation of the object.

Source code in formatting/models.py

def __str__(self) -> str:
    """Return the string representation of the object."""
    return str(self.name)

get_absolute_url()

Get the absolute URL of the object.

Source code in formatting/models.py

def get_absolute_url(self) -> str:
    """Get the absolute URL of the object."""
    return reverse("format:delimiter_index")

Extension

Bases: PermissionsBase

Extension of the data file.

It is mostly used to choose the tool to be employed to ingest the data. While it can take any value, there is currently explicit support only for xlsx and xlx. Anything else will be interpreted as a text file and loaded using pandas.read_csv.

Attributes:

Name	Type	Description
extension_id	AutoField	Primary key.
value	CharField	The extension value. eg. xlsx, xlx, txt.

Functions

__str__()

Return the string representation of the object.

Source code in formatting/models.py

def __str__(self) -> str:
    """Return the string representation of the object."""
    return str(self.value)

get_absolute_url()

Get the absolute URL of the object.

Source code in formatting/models.py

def get_absolute_url(self) -> str:
    """Get the absolute URL of the object."""
    return reverse("format:extension_index")

Format

Bases: PermissionsBase

Details of the data file format, describing how to read the file.

It combines several properties, such as the file extension, the delimiter, the date and time formats, and the column indices for the date and time columns, instructing how to read the data file and parse the dates. It is mostly used to ingest data from text files, like CSV.

Attributes:

Name	Type	Description
format_id	AutoField	Primary key.
name	CharField	Short name of the format entry.
description	TextField	Description of the format.
extension	ForeignKey	The extension of the data file.
delimiter	ForeignKey	The delimiter between columns in the data file. Only required for text files.
first_row	PositiveSmallIntegerField	Index of the first row with data, starting in 0.
footer_rows	PositiveSmallIntegerField	Number of footer rows to be ignored at the end.
date	ForeignKey	Format for the date column. Only required for text files.
date_column	PositiveSmallIntegerField	Index of the date column, starting in 0.
time	ForeignKey	Format for the time column. Only required for text files.
time_column	PositiveSmallIntegerField	Index of the time column, starting in 0.

Attributes

datetime_format: str property

Obtain the datetime format string.

Functions

__str__()

Return the string representation of the object.

Source code in formatting/models.py

def __str__(self) -> str:
    """Return the string representation of the object."""
    return str(self.name)

datetime_columns(delimiter)

Column indices that correspond to the date and time columns in the dataset.

Parameters:

Name	Type	Description	Default
delimiter	str	The delimiter used to split the date and time codes.	required

Returns:

Type	Description
list[int]	list[int]: A list of column indices.

Source code in formatting/models.py

def datetime_columns(self, delimiter: str) -> list[int]:
    """Column indices that correspond to the date and time columns in the dataset.

    Args:
        delimiter (str): The delimiter used to split the date and time codes.

    Returns:
        list[int]: A list of column indices.
    """
    date_items = self.date.code.split(delimiter)
    date_cols = list(range(self.date_column, self.date_column + len(date_items)))
    time_items = self.time.code.split(delimiter)
    time_cols = list(range(self.time_column, self.time_column + len(time_items)))
    return date_cols + time_cols

get_absolute_url()

Get the absolute URL of the object.

Source code in formatting/models.py

def get_absolute_url(self) -> str:
    """Get the absolute URL of the object."""
    return reverse("format:format_detail", kwargs={"pk": self.pk})

Time

Bases: PermissionsBase

Time format.

Format string for the time column. It is used to parse the time column in the data file. The format string must be compatible with the datetime module in Python. See the datetime documentation for more information on valid format codes.

Attributes:

Name	Type	Description
date_id	AutoField	Primary key.
date_format	CharField	The format string for the date column in human readable form, eg. HH:MM:SS 24H.
code	CharField	The code used to parse the date column, eg. %H:%M:%S.

Functions

__str__()

Return the string representation of the object.

Source code in formatting/models.py

def __str__(self) -> str:
    """Return the string representation of the object."""
    return str(self.time_format)

get_absolute_url()

Get the absolute URL of the object.

Source code in formatting/models.py

def get_absolute_url(self) -> str:
    """Get the absolute URL of the object."""
    return reverse("format:time_detail", kwargs={"pk": self.pk})

Variable

Bases: PermissionsBase

A variable with a physical meaning.

Such as precipitation, wind speed, wind direction, soil moisture, including the associated unit. It also includes metadata to help identify what is a reasonable value for the data, to flag outliers and to help with the validation process.

The nature of the variable can be one of the following:

• sum: Cumulative value over a period of time.
• average: Average value over a period of time.
• value: One-off value.

Attributes:

Name	Type	Description
variable_id	AutoField	Primary key.
variable_code	CharField	Code of the variable, eg. airtemperature.
name	CharField	Human-readable name of the variable, eg. Air temperature.
unit	ForeignKey	Unit of the variable.
maximum	DecimalField	Maximum value allowed for the variable.
minimum	DecimalField	Minimum value allowed for the variable.
diff_error	DecimalField	If two sequential values in the time-series data of this variable differ by more than this value, the validation process can mark this with an error flag.
outlier_limit	DecimalField	The statistical deviation for defining outliers, in times the standard deviation (sigma).
null_limit	DecimalField	The max % of null values (missing, caused by e.g. equipment malfunction) allowed for hourly, daily, monthly data. Cumulative values are not deemed trustworthy if the number of missing values in a given period is greater than the null_limit.
nature	CharField	Nature of the variable, eg. if it represents a one-off value, the average over a period of time or the cumulative value over a period

Attributes

is_cumulative: bool property

Return True if the nature of the variable is sum.

Functions

__str__()

Return the string representation of the object.

Source code in variable/models.py

def __str__(self) -> str:
    """Return the string representation of the object."""
    return str(self.name)

clean()

Validate the model fields.

Source code in variable/models.py

def clean(self) -> None:
    """Validate the model fields."""
    if self.maximum < self.minimum:
        raise ValidationError(
            {
                "maximum": "The maximum value must be greater than the minimum "
                "value."
            }
        )
    if not self.variable_code.isidentifier():
        raise ValidationError(
            {
                "variable_code": "The variable code must be a valid Python "
                "identifier. Only letters, numbers and underscores are allowed, and"
                " it cannot start with a number."
            }
        )
    return super().clean()

get_absolute_url()

Get the absolute URL of the object.

Source code in variable/models.py

def get_absolute_url(self) -> str:
    """Get the absolute URL of the object."""
    return reverse("variable:variable_detail", kwargs={"pk": self.pk})