polars.read_excel#

polars.read_excel(
source: str | Path | IO[bytes] | bytes,
*,
sheet_id: int | Sequence[int] | None = None,
sheet_name: str | list[str] | tuple[str] | None = None,
engine: ExcelSpreadsheetEngine = 'calamine',
engine_options: dict[str, Any] | None = None,
read_options: dict[str, Any] | None = None,
has_header: bool = True,
columns: Sequence[int] | Sequence[str] | None = None,
schema_overrides: SchemaDict | None = None,
infer_schema_length: int | None = 100,
drop_empty_rows: bool = True,
raise_if_empty: bool = True,
) → DataFrame | dict[str, DataFrame][source]#

Read Excel spreadsheet data into a DataFrame.

Changed in version 1.0: Default engine is now “calamine” (was “xlsx2csv”).

Added in version 0.20.6: Added “calamine” fastexcel engine for Excel Workbooks (.xlsx, .xlsb, .xls).

Added in version 0.19.3: Added “openpyxl” engine, and added schema_overrides parameter.

Parameters:
source

Path to a file or a file-like object (by “file-like object” we refer to objects that have a read() method, such as a file handler like the builtin open function, or a BytesIO instance). For file-like objects, stream position may not be updated accordingly after reading.

sheet_id

Sheet number(s) to convert (set 0 to load all sheets as DataFrames) and return a {sheetname:frame,} dict. (Defaults to 1 if neither this nor sheet_name are specified). Can also take a sequence of sheet numbers.

sheet_name

Sheet name(s) to convert; cannot be used in conjunction with sheet_id. If more than one is given then a {sheetname:frame,} dict is returned.

engine{‘calamine’, ‘xlsx2csv’, ‘openpyxl’}

Library used to parse the spreadsheet file; defaults to “calamine”.

  • “calamine”: this engine can be used for reading all major types of Excel Workbook (.xlsx, .xlsb, .xls) and is dramatically faster than the other options, using the fastexcel module to bind the Calamine parser.

  • “xlsx2csv”: converts the data to an in-memory CSV before using the native polars read_csv method to parse the result. You can pass engine_options and read_options to refine the conversion.

  • “openpyxl”: this engine is significantly slower than xlsx2csv but supports additional automatic type inference; potentially useful if you are otherwise unable to parse your sheet with the xlsx2csv engine in conjunction with the schema_overrides parameter.

engine_options

Additional options passed to the underlying engine’s primary parsing constructor (given below), if supported:

  • “calamine”: n/a (can only provide read_options)

  • “xlsx2csv”: Xlsx2csv

  • “openpyxl”: load_workbook

read_options

Options passed to the underlying engine method that reads the sheet data. Where supported, this allows for additional control over parsing. The specific read methods associated with each engine are:

  • “calamine”: ExcelReader.load_sheet_by_name

  • “xlsx2csv”: pl.read_csv

  • “openpyxl”: n/a (can only provide engine_options)

has_header

Indicate if the first row of the table data is a header or not. If False, column names will be autogenerated in the following format: column_x, with x being an enumeration over every column in the dataset, starting at 1.

columns

Columns to read from the sheet; if not specified, all columns are read. Can be given as a sequence of column names or indices.

schema_overrides

Support type specification or override of one or more columns.

infer_schema_length

The maximum number of rows to scan for schema inference. If set to None, the entire dataset is scanned to determine the dtypes, which can slow parsing for large workbooks. Note that only the “calamine” and “xlsx2csv” engines support this parameter.

drop_empty_rows

Indicate whether to omit empty rows when reading data into the DataFrame.

raise_if_empty

When there is no data in the sheet,`NoDataError` is raised. If this parameter is set to False, an empty DataFrame (with no columns) is returned instead.

Returns:
DataFrame

If reading a single sheet.

dict

If reading multiple sheets, a “{sheetname: DataFrame, …}” dict is returned.

See also

read_ods

Notes

  • Where possible, prefer the default “calamine” engine for reading Excel Workbooks, as it is significantly faster than the other options.

  • When using the xlsx2csv engine the target Excel sheet is first converted to CSV using xlsx2csv.Xlsx2csv(source).convert() and then parsed with Polars’ read_csv() function. You can pass additional options to read_options to influence this part of the parsing pipeline.

  • If you want to read multiple sheets and set different options (read_options, schema_overrides, etc), you should make separate calls as the options are set globally, not on a per-sheet basis.

Examples

Read the “data” worksheet from an Excel file into a DataFrame.

>>> pl.read_excel(
...     source="test.xlsx",
...     sheet_name="data",
... )

If the correct dtypes can’t be determined, use the schema_overrides parameter to specify them, or increase the inference length with infer_schema_length.

>>> pl.read_excel(
...     source="test.xlsx",
...     schema_overrides={"dt": pl.Date},
...     infer_schema_length=None,
... )

Using the xlsx2csv engine, read table data from sheet 3 in an Excel workbook as a DataFrame while skipping empty lines in the sheet. As sheet 3 does not have a header row, you can pass the necessary additional settings for this to the read_options parameter; these will be passed to read_csv().

>>> pl.read_excel(
...     source="test.xlsx",
...     sheet_id=3,
...     engine="xlsx2csv",
...     engine_options={"skip_empty_lines": True},
...     read_options={"has_header": False, "new_columns": ["a", "b", "c"]},
... )
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