Source code for grass.grassdb.data

"""
Manipulate data in mapsets in GRASS GIS Spatial Database

(C) 2020 by the GRASS Development Team
This program is free software under the GNU General Public
License (>=v2). Read the file COPYING that comes with GRASS
for details.

.. sectionauthor:: Vaclav Petras <wenzeslaus gmail com>
"""

import grass.script as gs


def map_exists(name, element, mapset=None, env=None):
    """Check is map is present in the mapset given in the environment

    :param name: Name of the map
    :param element: Data type ('raster', 'raster_3d', and 'vector')
    :param env: Environment created by function grass.script.create_environment
    :param mapset: Mapset name, "." for current mapset only,
                   None for all mapsets in the search path
    """
    # change type to element used by find file
    if element == "raster":
        element = "cell"
    elif element == "raster_3d":
        element = "grid3"
    # g.findfile returns non-zero when file was not found
    # se we ignore return code and just focus on stdout
    process = gs.start_command(
        "g.findfile",
        flags="n",
        element=element,
        file=name,
        mapset=mapset,
        stdout=gs.PIPE,
        stderr=gs.PIPE,
        env=env,
    )
    output, unused_errors = process.communicate()
    info = gs.parse_key_val(output, sep="=")
    # file is the key questioned in grass.script.core find_file()
    # return code should be equivalent to checking the output
    if info["file"]:
        return True
    return False