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Snipe CLI Documentation

sketch(ctx, sample, ref, amplicon, ychr, name, output_file, batch_size, cores, ksize, scale, force, debug)

Sketch genomic data to generate signatures for QC.

Only one input type (--sample, --ref, or --amplicon) can be specified at a time.

Usage

snipe sketch [OPTIONS]

Options

  • -s, --sample PATH
    Sample FASTA file.

  • -r, --ref PATH
    Reference genome FASTA file.

  • -a, --amplicon PATH
    Amplicon FASTA file.

  • --ychr PATH
    Y chromosome FASTA file (overrides the reference ychr).

  • -n, --name TEXT [required]
    Signature name.

  • -o, --output-file PATH [required]
    Output file with .zip extension.

  • -b, --batch-size INTEGER [default: 100000]
    Batch size for sample sketching.

  • -c, --cores INTEGER [default: 4]
    Number of CPU cores to use.

  • -k, --ksize INTEGER [default: 51]
    K-mer size.

  • -f, --force
    Overwrite existing output file.

  • --scale INTEGER [default: 10000]
    Sourmash scale factor.

  • --debug
    Enable debugging.

Examples

Sketching a Reference Genome

Generate a sketch from a reference genome FASTA file.

snipe sketch -r reference.fasta -n genome_ref -o genome_output.zip --cores 8 --debug
Sketching a Sample FASTA File

Generate a sketch from a sample FASTA file.

snipe sketch -s sample.fasta -n sample_name -o sample_output.zip
Sketching an Amplicon FASTA File with Custom Batch Size
snipe sketch -a amplicon.fasta -n amplicon_name -o amplicon_output.zip -b 50000
Overwriting an Existing Output File
snipe sketch -r reference.fasta -n genome_ref -o genome_output.zip --force
Using a Custom Y Chromosome File
snipe sketch -r reference.fasta -n genome_ref -o genome_output.zip --ychr custom_y.fasta
Source code in src/snipe/cli/cli_sketch.py
@click.command()
@click.option('-s', '--sample', type=click.Path(exists=True), help='Sample FASTA file.')
@click.option('-r', '--ref', type=click.Path(exists=True), help='Reference genome FASTA file.')
@click.option('-a', '--amplicon', type=click.Path(exists=True), help='Amplicon FASTA file.')
@click.option('--ychr', type=click.Path(exists=True), help='Y chromosome FASTA file (overrides the reference ychr).')
@click.option('-n', '--name', required=True, help='Signature name.')
@click.option('-o', '--output-file', required=True, callback=validate_zip_file, help='Output file with .zip extension.')
@click.option('-b', '--batch-size', default=100000, type=int, show_default=True, help='Batch size for sample sketching.')
@click.option('-c', '--cores', default=4, type=int, show_default=True, help='Number of CPU cores to use.')
@click.option('-k', '--ksize', default=51, type=int, show_default=True, help='K-mer size.')
@click.option('-f', '--force', is_flag=True, help='Overwrite existing output file.')
@click.option('--scale', default=10000, type=int, show_default=True, help='sourmash scale factor.')
@click.option('--debug', is_flag=True, default=False, hidden=True, help='Enable debugging.')
@click.pass_context
def sketch(ctx, sample: Optional[str], ref: Optional[str], amplicon: Optional[str],
           ychr: Optional[str], name: str, output_file: str, batch_size: int,
           cores: int, ksize: int, scale: int, force: bool, debug: bool):
    """
    Sketch genomic data to generate signatures for QC.

    Only one input type (`--sample`, `--ref`, or `--amplicon`) can be specified at a time.

    ## Usage

    ```bash
    snipe sketch [OPTIONS]
    ```

    ## Options

    - `-s`, `--sample PATH`  
      Sample FASTA file.

    - `-r`, `--ref PATH`  
      Reference genome FASTA file.

    - `-a`, `--amplicon PATH`  
      Amplicon FASTA file.

    - `--ychr PATH`  
      Y chromosome FASTA file (overrides the reference ychr).

    - `-n`, `--name TEXT` **[required]**  
      Signature name.

    - `-o`, `--output-file PATH` **[required]**  
      Output file with `.zip` extension.

    - `-b`, `--batch-size INTEGER` **[default: 100000]**  
      Batch size for sample sketching.

    - `-c`, `--cores INTEGER` **[default: 4]**  
      Number of CPU cores to use.

    - `-k`, `--ksize INTEGER` **[default: 51]**  
      K-mer size.

    - `-f`, `--force`  
      Overwrite existing output file.

    - `--scale INTEGER` **[default: 10000]**  
      Sourmash scale factor.

    - `--debug`  
      Enable debugging.

    ## Examples

    ### Sketching a Reference Genome

    Generate a sketch from a reference genome FASTA file.

    ```bash
    snipe sketch -r reference.fasta -n genome_ref -o genome_output.zip --cores 8 --debug
    ```

    ### Sketching a Sample FASTA File

    Generate a sketch from a sample FASTA file.

    ```bash
    snipe sketch -s sample.fasta -n sample_name -o sample_output.zip
    ```

    ### Sketching an Amplicon FASTA File with Custom Batch Size

    ```bash
    snipe sketch -a amplicon.fasta -n amplicon_name -o amplicon_output.zip -b 50000
    ```

    ### Overwriting an Existing Output File

    ```bash
    snipe sketch -r reference.fasta -n genome_ref -o genome_output.zip --force
    ```

    ### Using a Custom Y Chromosome File

    ```bash
    snipe sketch -r reference.fasta -n genome_ref -o genome_output.zip --ychr custom_y.fasta
    ```
    """
    samples = [sample, ref, amplicon]
    provided = [s for s in samples if s]
    if len(provided) != 1:
        click.echo('Error: Exactly one of --sample, --ref, or --amplicon must be provided.')
        sys.exit(1)

    # Handle existing output file
    if os.path.exists(output_file):
        if force:
            try:
                os.remove(output_file)
                click.echo(f"Overwriting existing output file {output_file}.")
            except Exception as e:
                click.echo(f"Failed to remove existing file {output_file}: {e}")
                sys.exit(1)
        else:
            click.echo(f"Output file {output_file} already exists. Please provide a new output file or use --force to overwrite.")
            sys.exit(1)

    # Determine the mode and set SigType accordingly
    if sample:
        mode = 'sample'
        sig_type = SigType.SAMPLE
        input_file = sample
    elif ref:
        mode = 'ref'
        sig_type = SigType.GENOME
        input_file = ref
    elif amplicon:
        mode = 'amplicon'
        sig_type = SigType.AMPLICON
        input_file = amplicon
    else:
        # This should not happen due to mutual exclusivity check
        raise click.UsageError('You must specify one of --sample, --ref, or --amplicon.')

    # Instantiate and execute SnipeSketch with logging based on debug flag
    try:
        sketcher = SnipeSketch(enable_logging=debug)
    except Exception as e:
        click.echo(f'Error instantiating SnipeSketch: {e}')
        sys.exit(1)

    # Sketching start time
    start_time = time.time()

    try:
        if sig_type == SigType.SAMPLE:
            # Modify sample name for clarity
            snipe_modification_to_name = f"{name}-snipesample"
            # Perform sample sketching
            sample_signature, total_bases = sketcher.sample_sketch(
                filename=sample,
                sample_name=snipe_modification_to_name,
                num_processes=cores,
                batch_size=batch_size,
                ksize=ksize,
                scale=scale,
            )
            # Export the signature to a ZIP file
            SnipeSketch.export_sigs_to_zip(
                [sample_signature],
                output_file,
            )

            click.echo(f"Sample {snipe_modification_to_name} sketching completed with {total_bases} bases")

        elif sig_type == SigType.GENOME:
            # Print sketching parameters for user information
            click.echo(f"Sketching genome with ksize={ksize}, scale={scale}, cores={cores}")

            snipe_modification_to_name = f"{name}-snipegenome"
            # Perform genome sketching
            genome_sig, chr_to_sig = sketcher.parallel_genome_sketching(
                fasta_file=ref,
                cores=cores,
                ksize=ksize,
                scale=scale,
                assigned_genome_name=snipe_modification_to_name,
            )

            # Rename genome signature for consistency
            genome_sig.name = snipe_modification_to_name

            # If Y chromosome is provided, perform amplicon sketching
            if ychr:
                if not sig_type == SigType.GENOME:
                    click.echo("Error: --ychr is only applicable with --ref.")
                    sys.exit(1)
                snipe_ychr_name = "sex-y"
                y_chr_sig = sketcher.amplicon_sketching(
                    fasta_file=ychr,
                    ksize=ksize, 
                    scale=scale,
                    amplicon_name=snipe_ychr_name,
                )
                chr_to_sig[snipe_ychr_name] = y_chr_sig

            # Log the detected chromosomes
            autosomal = [name for name in chr_to_sig.keys() if "autosome" in name.lower()]
            sex = [name for name in chr_to_sig.keys() if "sex" in name.lower()]
            mitochondrial = [name for name in chr_to_sig.keys() if "mito" in name.lower()]

            click.echo("Autodetected chromosomes:")
            for i, chr_name in enumerate(chr_to_sig.keys(), 1):
                print(f"{chr_name}", end="\t")
                if i % 6 == 0:
                    click.echo()
            if len(chr_to_sig) % 6 != 0:
                click.echo()  # For newline after the last line

            click.echo(f"Autosomal chromosomes: {len(autosomal)}, Sex chromosomes: {len(sex)}, Mitochondrial: {len(mitochondrial)}")

            # Export genome and chromosome signatures to a ZIP file
            SnipeSketch.export_sigs_to_zip(
                [genome_sig] + list(chr_to_sig.values()),
                output_file,
            )

        elif sig_type == SigType.AMPLICON:
            snipe_modification_to_name = f"{name}-snipeamplicon"
            # Perform amplicon sketching
            amplicon_signature = sketcher.amplicon_sketching(
                fasta_file=amplicon,
                ksize=ksize,
                scale=scale,
                amplicon_name=snipe_modification_to_name,
            )
            # Export the signature to a ZIP file
            SnipeSketch.export_sigs_to_zip(
                [amplicon_signature],
                output_file,
            )

    except Exception as e:
        click.echo(f"Error during sketching: {e}")
        sys.exit(1)

    # Sketching end time
    end_time = time.time()
    elapsed_time = end_time - start_time
    click.echo(f"Sketching completed in {elapsed_time:.2f} seconds.")