polars.read_excel#

polars.read_excel(
source: str | BytesIO | Path | BinaryIO | bytes,
*,
sheet_id: int | Sequence[int] | None = None,
sheet_name: str | list[str] | tuple[str] | None = None,
engine: ExcelSpreadsheetEngine | None = None,
engine_options: dict[str, Any] | None = None,
read_options: dict[str, Any] | None = None,
schema_overrides: SchemaDict | None = None,
raise_if_empty: bool = True,
) DataFrame | dict[str, DataFrame][source]#

Read Excel spreadsheet data into a DataFrame.

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

New in version 0.19.4: Added “pyxlsb” engine for Excel Binary Workbooks (.xlsb).

New 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 (e.g. via builtin open function) or BytesIO).

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

Library used to parse the spreadsheet file; currently defaults to “xlsx2csv” if not explicitly set.

  • “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 (default) xlsx2csv engine in conjunction with the schema_overrides parameter.

  • “pyxlsb”: this engine is used for Excel Binary Workbooks (.xlsb files). Note that you have to use schema_overrides to correctly load date/datetime columns (or these will be read as floats representing offset Julian values).

  • “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 calamine.

engine_options

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

  • “xlsx2csv”: Xlsx2csv

  • “openpyxl”: load_workbook

  • “pyxlsb”: open_workbook

  • “calamine”: n/a

read_options

Extra options passed to the function that reads the sheet data (for example, the read_csv method if using the “xlsx2csv” engine, to which you could pass {"infer_schema_length": None}, or the load_sheet_by_name method if using the “calamine” engine.

schema_overrides

Support type specification or override of one or more columns.

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.

Notes

When using the default 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.

Examples

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

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

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 and the default engine is xlsx2csv 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_options={"skip_empty_lines": True},
...     read_options={"has_header": False, "new_columns": ["a", "b", "c"]},
... )  

If the correct datatypes can’t be determined you can use schema_overrides and/or some of the read_csv() documentation to see which options you can pass to fix this issue. For example "infer_schema_length": None can be used to read the data twice, once to infer the correct output types and once more to then read the data with those types. If the types are known in advance then schema_overrides is the more efficient option.

>>> pl.read_excel(
...     source="test.xlsx",
...     read_options={"infer_schema_length": 1000},
...     schema_overrides={"dt": pl.Date},
... )  

The openpyxl package can also be used to parse Excel data; it has slightly better default type detection, but is slower than xlsx2csv. If you have a sheet that is better read using this package you can set the engine as “openpyxl” (if you use this engine then read_options cannot be set).

>>> pl.read_excel(
...     source="test.xlsx",
...     engine="openpyxl",
...     schema_overrides={"dt": pl.Datetime, "value": pl.Int32},
... )