lazer.utils

General utility functions that are not specific to lidar processing workflows.

LazerParser (ArgumentParser)

error(self, message)

error(message: string)

Prints a usage message incorporating the message to stderr and exits.

If you override this in a subclass, it should not return -- it should either exit or raise an exception.

Source code in lazer/utils.py

def error(self, message):
    self.print_help()
    sys.stderr.write(f"\nerror: {message}\n")
    sys.exit(2)

add_raster_metadata(file_path, custom_metadata)

Adds custom metadata tags to a raster's header.

Source code in lazer/utils.py

def add_raster_metadata(file_path: str, custom_metadata: dict) -> None:
    """Adds custom metadata tags to a raster's header."""
    ref = gdal.Open(file_path, gdal.GA_Update)
    metadata = ref.GetMetadata_Dict()
    for key, value in custom_metadata.items():
        metadata[key] = value
    ref.SetMetadata(metadata)
    ref.FlushCache()
    ref = None

input_files_to_list(input_files)

Parses a list of input file arguments, which may include wildcards, into a single list.

Parameters:

Name	Type	Description	Default
input_files	list	list of file paths passed at the command line.	required

Returns:

Type	Description
list	a single list with each wildcard entry expanded.

Source code in lazer/utils.py

def input_files_to_list(input_files: list) -> list:
    """Parses a list of input file arguments, which may include wildcards, into a single list.

    Args:
        input_files: list of file paths passed at the command line.

    Returns:
        a single list with each wildcard entry expanded.
    """
    output_list = []
    for input_arg in input_files:
        search_result = glob(input_arg)
        output_list += search_result
    return output_list

input_files_to_lof(input_files, lof_path)

Parses input file arguments and writes to a lastools 'list of files' file.

Parameters:

Name	Type	Description	Default
input_files	list	list of file paths passed at the command line.	required
lof_path	str	output text file with one file path per line.	required

Source code in lazer/utils.py

def input_files_to_lof(input_files: list, lof_path: str) -> None:
    """Parses input file arguments and writes to a lastools 'list of files' file.

    Args:
        input_files: list of file paths passed at the command line.
        lof_path: output text file with one file path per line.
    """
    list_to_lof(input_files_to_list(input_files), lof_path)

list_to_lof(file_list, lof_path)

Writes a list of file paths to a lastools "list of files" file.

Source code in lazer/utils.py

def list_to_lof(file_list: list, lof_path: str) -> None:
    """Writes a list of file paths to a lastools "list of files" file."""
    with open(lof_path, "w+") as f:
        [f.write(f"{filename}\n") for filename in file_list]

read_file_list(file_path)

Reads an ascii file returns a list containing each line's entry.

Source code in lazer/utils.py

def read_file_list(file_path: str) -> list:
    """Reads an ascii file returns a list containing each line's entry."""
    with open(file_path, "r") as handler:
        contents = handler.read()
    return contents.strip().split("\n")

run_command_line(command)

Run a shell command via subproces and assert no error.

Parameters:

Name	Type	Description	Default
command	str	the shell command string to run.	required

Returns:

Type	Description
str	stdout from completed process.

Source code in lazer/utils.py

def run_command_line(command: str) -> str:
    """Run a shell command via subproces and assert no error.

    Args:
      command: the shell command string to run.

    Returns:
      stdout from completed process.
    """
    _logger.debug("Running command:  {}".format(command))
    completed = subprocess.run(
        shlex.split(command), stdout=subprocess.PIPE, stderr=subprocess.PIPE
    )

    if completed.stderr:
        message = "\n\n".join(
            [
                command,
                f"stdout: {completed.stdout.decode('utf-8')}",
                f"stderr: {completed.stderr.decode('utf-8')}",
            ]
        )
        assert completed.returncode == 0, message

    return completed.stdout.decode("utf-8")