The issue seems to be with the trailing white space in the value. When setting the value of 'Exif.GPSInfo.GPSVersionID' to '2 0 0 0', this works as expected (with libexiv2 0.20).
It is easy enough to suppress trailing spaces on the fly and to make sure that pyexiv2.utils.string_to_undefined(...) returns strings with no trailing spaces. I will add corresponding unit tests.
The issue seems to be with the trailing white space in the value. When setting the value of 'Exif.GPSInfo. GPSVersionID' to '2 0 0 0', this works as expected (with libexiv2 0.20). utils.string_ to_undefined( ...) returns strings with no trailing spaces. I will add corresponding unit tests.
It is easy enough to suppress trailing spaces on the fly and to make sure that pyexiv2.