test_csw.py

from geolinks import sniff_link
from owslib.csw import CatalogueServiceWeb
from owslib.fes import (
    And,
    BBox,
    Or,
    PropertyIsEqualTo,
    PropertyIsGreaterThanOrEqualTo,
    PropertyIsLessThanOrEqualTo,
    PropertyIsLike,
)


csw_test_endpoint = "https://nbs.csw.met.no"
ElementSetName = "full"

start_time = "2023-10-01 00:00"
end_time = "2023-10-02 00:00"

csw = CatalogueServiceWeb(csw_test_endpoint, timeout=60)


# Create filters
filter1 = PropertyIsLessThanOrEqualTo(
    propertyname="apiso:TempExtent_begin", literal=f"{end_time}"
)
filter2 = PropertyIsGreaterThanOrEqualTo(
    propertyname="apiso:TempExtent_end", literal=f"{start_time}"
)

# Combine filters
filter = And([filter1, filter2])

# Use the filter in a CSW getrecords request
csw.getrecords2(
    constraints=[filter],
    esn=f"{ElementSetName}",
    startposition=1,
    maxrecords=5,
)

# the following returns ... 7153  (isn't it too much?

csw.results['matches']


#####

print("Found {} records.\n".format(len(csw.records.keys())))
for key, value in list(csw.records.items()):

    print("Title: [{}]\nID: {}\n".format(value.title, key))
    filtered_attributes = [attr for attr in dir(value) if not attr.startswith("_")]
    if 'bbox' in filtered_attributes:
        print('bbox: ', value.bbox.maxx, value.bbox.maxy, value.bbox.minx, value.bbox.miny)
    msg = "geolink: {geolink}\nscheme: {scheme}\nURL: {url}\n".format
    for ref in value.references:
        print(msg(geolink=sniff_link(ref["url"]), **ref))
    print("#########################################################", "\n")
    
    

Note:

csw.getrecords2(
    constraints=[filter],
    esn=f"{ElementSetName}",
    startposition=1,
    maxrecords=5,
)

returns 5 records, even if you set maxrecord>=10 , for how is set-up the server, - it will always return max 10 elements at the time.
means you have to loop through all found records using the csw.results['matches'] value.