DRF Excel: Django REST Framework Excel Spreadsheet (xlsx) Renderer

drf-excel provides an Excel spreadsheet (xlsx) renderer for Django REST Framework. It uses OpenPyXL to create the spreadsheet and provide the file to the end user.

Requirements

We aim to support Django’s currently supported versions, as well as:

  • Django REST Framework >= 3.6
  • OpenPyXL >= 2.4

Installation

pip install drf-excel

Then add the following to your REST_FRAMEWORK settings:

REST_FRAMEWORK = {
    ...

    'DEFAULT_RENDERER_CLASSES': (
        'rest_framework.renderers.JSONRenderer',
        'rest_framework.renderers.BrowsableAPIRenderer',
        'drf_excel.renderers.XLSXRenderer',
    ),
}

To avoid having a file streamed without a filename (which the browser will often default to the filename “download”, with no extension), we need to use a mixin to override the Content-Disposition header. If no filename is provided, it will default to export.xlsx. For example:

from rest_framework.viewsets import ReadOnlyModelViewSet
from drf_excel.mixins import XLSXFileMixin
from drf_excel.renderers import XLSXRenderer

from .models import MyExampleModel
from .serializers import MyExampleSerializer

class MyExampleViewSet(XLSXFileMixin, ReadOnlyModelViewSet):
    queryset = MyExampleModel.objects.all()
    serializer_class = MyExampleSerializer
    renderer_classes = (XLSXRenderer,)
    filename = 'my_export.xlsx'

The XLSXFileMixin also provides a get_filename() method which can be overridden, if you prefer to provide a filename programmatically instead of the filename attribute.

Upgrading to 2.0.0

To upgrade to drf_excel 2.0.0 from drf_renderer_xlsx, update your import paths:

  • from drf_renderer_xlsx.mixins import XLSXFileMixin becomes from drf_excel.mixins import XLSXFileMixin.
  • drf_renderer_xlsx.renderers.XLSXRenderer becomes drf_excel.renderers.XLSXRenderer.
  • xlsx_date_format_mappings has been removed in favor of column_data_styles which provides more flexibility

Configuring Styles

Styles can be added to your worksheet header, column header row, body and column data from view attributes header, column_header, body, column_data_styles. Any arguments from the OpenPyXL package can be used for font, alignment, fill and border_side (border will always be all side of cell).

If provided, column data styles will override body style

Note that column data styles can take an extra ‘format’ argument that follows openpyxl formats.

class MyExampleViewSet(XLSXFileMixin, ReadOnlyModelViewSet):
    queryset = MyExampleModel.objects.all()
    serializer_class = MyExampleSerializer
    renderer_classes = (XLSXRenderer,)

    column_header = {
        'titles': [
            "Column_1_name",
            "Column_2_name",
            "Column_3_name",
        ],
        'column_width': [17, 30, 17],
        'height': 25,
        'style': {
            'fill': {
                'fill_type': 'solid',
                'start_color': 'FFCCFFCC',
            },
            'alignment': {
                'horizontal': 'center',
                'vertical': 'center',
                'wrapText': True,
                'shrink_to_fit': True,
            },
            'border_side': {
                'border_style': 'thin',
                'color': 'FF000000',
            },
            'font': {
                'name': 'Arial',
                'size': 14,
                'bold': True,
                'color': 'FF000000',
            },
        },
    }
    body = {
        'style': {
            'fill': {
                'fill_type': 'solid',
                'start_color': 'FFCCFFCC',
            },
            'alignment': {
                'horizontal': 'center',
                'vertical': 'center',
                'wrapText': True,
                'shrink_to_fit': True,
            },
            'border_side': {
                'border_style': 'thin',
                'color': 'FF000000',
            },
            'font': {
                'name': 'Arial',
                'size': 14,
                'bold': False,
                'color': 'FF000000',
            }
        },
        'height': 40,
    }
    column_data_styles = {
        'distance': {
            'alignment': {
                'horizontal': 'right',
                'vertical': 'top',
            },
            'format': '0.00E+00'
        },
        'created_at': {
            'format': 'd.m.y h:mm',
        }
    }

You can dynamically generate style attributes in methods get_body, get_header, get_column_header, get_column_data_styles.

def get_header(self):
    start_time, end_time = parse_times(request=self.request)
    datetime_format = "%H:%M:%S %d.%m.%Y"
    return {
        'tab_title': 'MyReport', # title of tab/workbook
        'use_header': True,  # show the header_title 
        'header_title': 'Report from {} to {}'.format(
            start_time.strftime(datetime_format),
            end_time.strftime(datetime_format),
        ),
        'height': 45,
        'img': 'app/images/MyLogo.png',
        'style': {
            'fill': {
                'fill_type': 'solid',
                'start_color': 'FFFFFFFF',
            },
            'alignment': {
                'horizontal': 'center',
                'vertical': 'center',
                'wrapText': True,
                'shrink_to_fit': True,
            },
            'border_side': {
                'border_style': 'thin',
                'color': 'FF000000',
            },
            'font': {
                'name': 'Arial',
                'size': 16,
                'bold': True,
                'color': 'FF000000',
            }
        }
    }

Also, you can add color field to your serializer and fill body rows.

class ExampleSerializer(serializers.Serializer):
    color = serializers.SerializerMethodField()

    def get_color(self, instance):
        color_map = {'w': 'FFFFFFCC', 'a': 'FFFFCCCC'}
        return color_map.get(instance.alarm_level, 'FFFFFFFF')

Controlling XLSX headers and values

Use Serializer Field labels as header names

By default, headers will use the same ‘names’ as they are returned by the API. This can be changed by setting xlsx_use_labels = True inside your API View.

Instead of using the field names, the export will use the labels as they are defined inside your Serializer. A serializer field defined as title = serializers.CharField(label=_("Some title")) would return Some title instead of title, also supporting translations. If no label is set, it will fall back to using title.

Ignore fields

By default, all fields are exported, but you might want to exclude some fields from your export. To do so, you can set an array with fields you want to exclude: xlsx_ignore_headers = [<excluded fields>].

This also works with nested fields, separated with a dot (i.e. icon.url).

Date/time and number formatting

Formatting for cells follows openpyxl formats.

To set global formats, set the following variables in settings.py:

# Date formats
DRF_EXCEL_DATETIME_FORMAT = 'mm-dd-yy h:mm AM/PM'
DRF_EXCEL_DATE_FORMAT = 'mm-dd-yy'
DRF_EXCEL_TIME_FORMAT = 'h:mm AM/PM'

# Number formats
DRF_EXCEL_INTEGER_FORMAT = '0%'
DRF_EXCEL_DECIMAL_FORMAT = '0.00E+00'

Name boolean values

True and False as values for boolean fields are not always the best representation and don’t support translation.

This can be controlled with in you API view with xlsx_boolean_labels.

xlsx_boolean_labels = {True: _('Yes'), False: _('No')}

will replace True with Yes and False with No.

This can also be set globally in settings.py:

DRF_EXCEL_BOOLEAN_DISPLAY = {True: _('Yes'), False: _('No')}

Custom columns

You might find yourself explicitly returning a dict in your API response and would like to use its data to display additional columns. This can be done by passing xlsx_custom_cols.

xlsx_custom_cols = {
    'my_custom_col.val1.title': {
        'label': 'Custom column!',
        'formatter': custom_value_formatter
    }
}

### Example function:
def custom_value_formatter(val):
    return val + '!!!'

### Example response:
{ 
    results: [
        {
            title: 'XLSX renderer',
            url: 'https://github.com/wharton/drf-excel'
            returned_dict: {
                val1: {
                    title: 'Sometimes'
                },
                val2: {
                    title: 'There is no way around'
                }
            }
        }
    ]
}

When no label is passed, drf-excel will display the key name in the header.
formatter is also optional and accepts a function, which will then receive the value it is mapped to (it would receive “Sometimes” and return “Sometimes!!!” in our example).

Custom mappings

Assuming you have a field that returns a dict instead of a simple str, you might not want to return the whole object but only a value of it. Let’s say status returns { value: 1, display: 'Active' }. To return the display value in the status column, we can do this:

xlsx_custom_mappings = {
    'status': 'display'
}

A probably more common case is that you want to change how a value is formatted. xlsx_custom_mappings also takes functions as values. Assuming we have a field description, and for some strange reason want to reverse the text, we can do this:

def reverse_text(val):
    return val[::-1]

xlsx_custom_mappings = {
    'description': reverse_text
}

Release Notes

Release notes are available on GitHub.

Maintainers

This package was created by the staff of Wharton Research Data Services. We are thrilled that The Wharton School allows us a certain amount of time to contribute to open-source projects. We add features as they are necessary for our projects, and try to keep up with Issues and Pull Requests as best we can. Due to constraints of time (our full time jobs!), Feature Requests without a Pull Request may not be implemented, but we are always open to new ideas and grateful for contributions and our users.

Contributors (Thank You!)

GitHub

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