How to get VLRs from a .las file with laspy

Question

I have a .las point cloud data file that I am trying to get the vlr data from. I have found this link - Update EVLR header info for .LAS file using laspy and have read the docs on Laspy - https://pythonhosted.org/laspy/header.html

It seems like the header vlrs should return a variable length record if it exists.

las_file =laspy.file.File(file.las, mode = "r-")
hdr = las_file.header
hformat = hdr.header_format
for spec in hformat:
    print(spec.name, spec.offs, spec.num)
    
inVLRs = hdr.vlrs
print(inVLRs)
vlr_count = len(inVLRs)
# OGC Coordinate System WKT
print(hdr.max, hdr.version, vlr_count)

I never get anything back for the vlrs. I get all other header info without an issue. Sample file here.

When I use WhiteBoxTools - I do get the correct VLR info. - https://pypi.org/project/whitebox/

Am I using the correct method to get vlrs?

Answer 1

The "r-" in the line las_file =laspy.file.File(file.las, mode = "r-") is the problem. I changed it to "r" and the problem is solved.