How to have only CSV, XLS, XLSX options in django-import-export?

This is old, but for those who might like to know...I can't comment above because I don't have "50 reputation". To extend Burhan Khalid's answer above, if you'd like to apply these format restrictions (or any overwritten methods of ExportMixin to multiple admin classes) you can create an abstract base class in the admin and then use that class for the classes you'd like to keep those overwrites.

from import_export.formats import base_formats

# use for all admins that are admin.ModelAdmin and use ExportMixin
class ExportMixinAdmin(ExportMixin, admin.ModelAdmin):

    # your normal stuff

    def get_export_formats(self):
        formats = (
          base_formats.CSV,
          base_formats.XLS,
          base_formats.XLSX,
          )

        return [f for f in formats if f().can_export()]

    class Meta:
        abstract = True

class ModelOneAdmin(ExportMixinAdmin):

    # your normal stuff here

class ModelTwoAdmin(ExportMixinAdmin):

    # your normal stuff here

You can override the get_export_formats() method of the ExportMixin:

from import_export.formats import base_formats


class MyAdmin(ExportMixin):
    # your normal stuff
    def get_export_formats(self):
            """
            Returns available export formats.
            """
            formats = (
                  base_formats.CSV,
                  base_formats.XLS,
                  base_formats.XLSX,
                  base_formats.TSV,
                  base_formats.ODS,
                  base_formats.JSON,
                  base_formats.YAML,
                  base_formats.HTML,
            )
            return [f for f in formats if f().can_export()]