Fix issue when headers are parsed and a NaN is encountered

CHANGELOG.md

@@ -19,6 +19,7 @@
 - Added tests for `ici.extract_params` ([#5](https://github.com/NatLabRockies/ampworks/pull/5))
 
 ### Bug Fixes
+- Catch when `NaN` is present when parsing for headers in excel files ([#23](https://github.com/NatLabRockies/ampworks/pull/23))
 - Force the `cell` dataset of the `DqdvFitter` to require an Ah column ([#19](https://github.com/NatLabRockies/ampworks/pull/19))
 - Update patching policy for releases, use `spellcheck` in nox pre-commit ([#13](https://github.com/NatLabRockies/ampworks/pull/13))
 - Readers missing name-only columns, e.g., `testtime` ([#8](https://github.com/NatLabRockies/ampworks/pull/8))

pyproject.toml

@@ -68,11 +68,11 @@ select = [
     "D",  # All pydocstyle checks
 ]
 extend-select = [
-    "E302",  # Expected 2 blank lines, found 1 (requires preview=true, above)
+    "E302", "E305",  # Expected blank lines (requires preview=true, above)
 ]
 ignore = [
-    "B007", "B009", "B028", "B905",
-    "D100", "D103", "D104", "D203", "D205", "D212", "D401",
+    "B007", "B009", "B010", "B028", "B905",
+    "D1", "D203", "D205", "D212", "D400", "D401", "D415",
     "E201", "E202", "E226", "E241", "E731",
 ]
 

src/ampworks/__init__.py

@@ -18,7 +18,7 @@
 the documentation by visiting the website, hosted on Read the Docs. The website
 includes search functionality and more detailed examples.
 
-"""  # noqa: D400, D415 (ignore missing punctuation on first line)
+"""
 
 from typing import TYPE_CHECKING
 

src/ampworks/_core/_read.py

@@ -1,7 +1,7 @@
 from __future__ import annotations
 
 from warnings import warn
-from typing import TYPE_CHECKING
+from typing import Sequence, TYPE_CHECKING
 
 import pandas as pd
 
@@ -11,7 +11,7 @@
 
 
 # Define expected headers and their aliases
-def format_alias(names: str, units: str) -> str:
+def format_alias(names: Sequence[str], units: Sequence[str]) -> list[str]:
 
     aliases = units.copy()  # units only
 
@@ -187,28 +187,34 @@ def read_table(filepath: PathLike) -> Dataset:
     return Dataset()
 
 
-def read_excel(filepath: PathLike, sheet_name: str | int | list = 'first',
-               stack_sheets: bool = False) -> Dataset:
+def read_excel(
+    filepath: PathLike,
+    sheet_name: str | int | list[int, str] | None = None,
+    stack_sheets: bool = False,
+) -> Dataset:
     """Read excel file."""
     from ampworks import Dataset
 
     workbook = pd.ExcelFile(filepath)
     all_sheets = workbook.sheet_names
     num_sheets = len(all_sheets)
 
-    # Warn if any sheet conflicts with 'first' or 'all'
-    if sheet_name == 'first' and 'first' in all_sheets:
-        warn()
-    elif sheet_name == 'all' and 'all' in all_sheets:
+    # warn if 'all' matches a sheet name
+    if sheet_name == 'all' and 'all' in all_sheets:
         warn()
 
     # Set which sheets to iterate through
-    if sheet_name in ['first', 'all']:
+    if sheet_name is None or sheet_name == 'all':
         iter_sheets = all_sheets
     elif isinstance(sheet_name, (str, int)):
         iter_sheets = [sheet_name]
+    elif isinstance(sheet_name, Sequence):
+        iter_sheets = list(sheet_name)
     else:
-        iter_sheets = sheet_name
+        raise TypeError(
+            "'sheet_name' expected a str, int, list[str, int], or None, but"
+            f" got {type(sheet_name)}."
+        )
 
     # Raise errors if invalid indices/names
     indices = [v for v in iter_sheets if isinstance(v, int)]
@@ -233,20 +239,21 @@ def read_excel(filepath: PathLike, sheet_name: str | int | list = 'first',
         # Find header row
         header_row = None
         for idx, row in preview.iterrows():
-            if header_matches(row.values.astype(str), REQUIRED_HEADERS):
+            tmp_headers = row.fillna('').astype(str).values
+            if header_matches(tmp_headers, REQUIRED_HEADERS):
                 header_row = idx
                 break
 
         if header_row is not None:
             df = workbook.parse(sheet, header=header_row)
             datasets[sheet] = standardize_headers(df)
-            if sheet_name == 'first':
+            if sheet_name is None:
                 break
         else:
             failed.append(sheet)
 
     # Prepare outputs
-    if sheet_name != 'first' and failed:
+    if sheet_name is None and failed:
         warn(f"Could not find valid headers in requested sheets: {failed}")
 
     if not datasets: