Fix #27 by catching NoDataError when trying to parse empty BLAST resu…

…lts files in parse_influenza_blast_results.py

CHANGELOG.md

@@ -3,6 +3,12 @@
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [[3.2.1](https://github.com/CFIA-NCFAD/nf-flu/releases/tag/3.2.1)] - 2023-07-07
+
+### Fixes
+
+* Empty BLAST results file parsing `NoDataError` (#27) (Thanks @MatFish for reporting this issue!)
+
 ## [[3.2.0](https://github.com/CFIA-NCFAD/nf-flu/releases/tag/3.2.0)] - 2023-06-22
 
 ### Added

bin/parse_influenza_blast_results.py

@@ -189,19 +189,27 @@ def parse_blast_result(
  top: int = 3,
  pident_threshold: float = 0.85,
  min_aln_length: int = 50,
-) -> Optional[
- Tuple[pl.DataFrame, Optional[pl.DataFrame], Optional[pl.DataFrame], Dict]
-]:
+) -> Optional[Tuple[pl.DataFrame, Dict]]:
  logging.info(f"Parsing BLAST results from {blast_result}")
 
- df_filtered = pl.scan_csv(
- blast_result,
- has_header=False,
- separator="\t",
- new_columns=[name for name, coltype in blast_cols],
- dtypes={name: coltype for name, coltype in blast_cols},
- ).filter((pl.col("pident") >= (pident_threshold * 100)) &
- (pl.col("length") >= min_aln_length)).collect(streaming=True)
+ try:
+ df_filtered = (
+ pl.scan_csv(
+ blast_result,
+ has_header=False,
+ separator="\t",
+ new_columns=[name for name, coltype in blast_cols],
+ dtypes=dict(blast_cols),
+ )
+ .filter(
+ (pl.col("pident") >= (pident_threshold * 100))
+ & (pl.col("length") >= min_aln_length)
+ )
+ .collect(streaming=True)
+ )
+ except pl.exceptions.NoDataError:
+ logging.warning(f"No BLAST results found in {blast_result}")
+ return None
 
  sample_name: str = re.sub(r"^(.+)_\d$", r"\1", df_filtered["qaccver"][0])
  logging.info(
@@ -231,22 +239,21 @@ def parse_blast_result(
  )
 
  segments = df_merge["sample_segment"].unique().sort()
- dfs = []
- for seg in segments:
- dfs.append(df_merge.filter(pl.col("sample_segment") == seg).head(top))
+ dfs = [
+ df_merge.filter(pl.col("sample_segment") == seg).head(top)
+ for seg in segments
+ ]
  df_top_seg_matches = pl.concat(dfs, how="vertical")
  cols = pl.Series([x for x, _ in blast_results_report_columns])
  df_top_seg_matches = df_top_seg_matches.select(pl.col(cols))
  subtype_results_summary = {"sample": sample_name}
  if not get_top_ref:
- is_iav = True
- if df_top_seg_matches.select(pl.col("subtype").is_null().all())[0, 0]:
- is_iav = False
+ is_iav = not df_top_seg_matches.select(pl.col("subtype").is_null().all())[0, 0]
  H_results = None
  N_results = None
  if "4" in segments:
  H_results = find_h_or_n_type(df_merge, "4", is_iav)
- subtype_results_summary.update(H_results)
+ subtype_results_summary |= H_results
  if "6" in segments:
  N_results = find_h_or_n_type(df_merge, "6", is_iav)
  subtype_results_summary.update(N_results)
@@ -258,27 +265,26 @@ def parse_blast_result(
 def get_subtype_value(H_results: Optional[Dict], N_results: Optional[Dict], is_iav: bool) -> str:
  subtype = ""
  if not is_iav:
- subtype = "N/A"
- return subtype
+ return "N/A"
  if H_results is None and N_results is None:
  subtype = "-"
  elif H_results is not None and N_results is None:
  H: str = H_results.get("H_type", "")
  subtype = f"H{H}" if H != "" else "-"
- elif H_results is None and N_results is not None:
+ elif H_results is None:
  N: str = N_results.get("N_type", "")
  subtype = f"N{N}" if N != "" else "-"
  else:
  H: str = H_results.get("H_type", "")
  N: str = N_results.get("N_type", "")
- if H == "" and N == "":
- subtype = "-"
- else:
+ if H or N:
  if H != "":
  H = f"H{H}"
  if N != "":
  N = f"N{N}"
  subtype = f"{H}{N}"
+ else:
+ subtype = "-"
  return subtype
 
 
@@ -289,40 +295,40 @@ def find_h_or_n_type(df_merge, seg, is_iav):
  ], "Can only determine H or N type from segments 4 or 6, respectively!"
  type_name = "H_type" if seg == "4" else "N_type"
  h_or_n = type_name[0]
- reg_h_or_n_type = ""
- if h_or_n == "H":
- reg_h_or_n_type = "[Hh]"
- else:
- reg_h_or_n_type = "[Nn]"
  df_segment = df_merge.filter(pl.col("sample_segment") == seg)
  if is_iav:
  type_counts = df_segment["subtype"].value_counts(sort=True)
  type_counts = type_counts.filter(~pl.col("subtype").is_null())
+ reg_h_or_n_type = "[Hh]" if h_or_n == "H" else "[Nn]"
  df_type_counts = type_counts.with_columns(pl.lit(type_counts["subtype"].str.extract(reg_h_or_n_type + r"(\d+)").
  alias(type_name)))
  df_type_counts = df_type_counts.filter(~pl.col(type_name).is_null())
  logging.debug(f"{df_type_counts}")
  type_to_count = defaultdict(int)
  for x in df_type_counts.iter_rows(named=True):
  type_to_count[x[type_name]] += x["counts"]
- type_to_count = [(h, c) for h, c in type_to_count.items()]
+ type_to_count = list(type_to_count.items())
  type_to_count.sort(key=lambda x: x[1], reverse=True)
  top_type, top_type_count = type_to_count[0]
  total_count = type_counts["counts"].sum()
  logging.info(
  f"{h_or_n}{top_type} n={top_type_count}/{total_count} ({top_type_count / total_count:.1%})"
  )
  df_segment = df_segment.with_columns(
- pl.lit(df_segment["subtype"].str.contains(r".*" + reg_h_or_n_type + top_type + r".*")
- .fill_null(False)
- .alias("type_mask")))
+ pl.lit(
+ df_segment["subtype"]
+ .str.contains(f".*{reg_h_or_n_type}" + top_type + r".*")
+ .fill_null(False)
+ .alias("type_mask")
+ )
+ )
  df_seg_top_type = df_segment.filter(pl.col("type_mask") == True).drop("type_mask")
- top_result: pl.Series = [r for r in df_seg_top_type.head(1).iter_rows(named=True)][0]
+ top_result: pl.Series = list(df_seg_top_type.head(1).iter_rows(named=True))[0]
  else:
  top_type = "N/A"
  top_type_count = "N/A"
  total_count = "N/A"
- top_result: pl.Series = [r for r in df_segment.head(1).iter_rows(named=True)][0]
+ top_result: pl.Series = list(df_segment.head(1).iter_rows(named=True))[0]
 
  results_summary = {
  f"{h_or_n}_type": top_type if is_iav else "N/A",
@@ -388,7 +394,7 @@ def report(flu_metadata, blast_results, excel_report, top, pident_threshold,
  has_header=False,
  separator="\t",
  new_columns=[name for name, _ in md_cols],
- dtypes={name: t for name, t in md_cols},
+ dtypes=dict(md_cols),
  )
 
  unique_subtypes = df_md.select("subtype").unique()
@@ -414,7 +420,7 @@ def report(flu_metadata, blast_results, excel_report, top, pident_threshold,
  sample = subtype_results_summary["sample"]
  all_subtype_results[sample] = subtype_results_summary
  df_all_blast = pd.concat(dfs_blast).rename(
- columns={k: v for k, v in blast_results_report_columns}
+ columns=dict(blast_results_report_columns)
  )
  df_subtype_results = pd.DataFrame(all_subtype_results).transpose()
  cols = pd.Series(subtype_results_summary_columns)
@@ -442,9 +448,7 @@ def report(flu_metadata, blast_results, excel_report, top, pident_threshold,
  )
  else:
  df_blast, subtype_results_summary = results[0]
- df_blast = df_blast.rename(
- mapping={k: v for k, v in blast_results_report_columns}
- )
+ df_blast = df_blast.rename(mapping=dict(blast_results_report_columns))
  df_ref_id = df_blast.select(pl.col(['Sample', 'Sample Genome Segment Number',
  'Reference NCBI Accession', 'BLASTN Bitscore', 'Reference Sequence ID']))
  df_ref_id = df_ref_id.with_columns(
@@ -463,10 +467,9 @@ def report(flu_metadata, blast_results, excel_report, top, pident_threshold,
 def get_col_widths(df, index=False):
  """Calculate column widths based on column headers and contents"""
  if index:
- idx_max = max(
+ yield max(
  [len(str(s)) for s in df.index.values] + [len(str(df.index.name))]
  )
- yield idx_max
  for c in df.columns:
  # get max length of column contents and length of column header
  yield np.max([df[c].astype(str).str.len().max() + 1, len(c) + 1])
@@ -493,7 +496,7 @@ def write_excel(
  # fixed max number of characters in sheet name due to compatibility
  if sheet_name_index:
  max_chars = 28
- fixed_sheetname = "{}_{}".format(idx, fixed_sheetname[:max_chars])
+ fixed_sheetname = f"{idx}_{fixed_sheetname[:max_chars]}"
  else:
  max_chars = 31
  fixed_sheetname = fixed_sheetname[:max_chars]
@@ -506,7 +509,7 @@ def write_excel(
  len(fixed_sheetname),
  )
 
- logging.info('Writing table to Excel sheet "{}"'.format(fixed_sheetname))
+ logging.info(f'Writing table to Excel sheet "{fixed_sheetname}"')
  df.to_excel(
  writer, sheet_name=fixed_sheetname, index=False, freeze_panes=(1, 1)
  )

nextflow.config

@@ -153,7 +153,7 @@ manifest {
  description = 'Influenza A virus genome assembly pipeline'
  homePage = 'https://github.com/CFIA-NCFAD/nf-flu'
  author = 'Peter Kruczkiewicz, Hai Nguyen'
- version = '3.2.0'
+ version = '3.2.1'
  nextflowVersion = '>=21.10'
  mainScript = 'main.nf'
  doi = '10.5281/zenodo.7011213'